GB2280674A - Pyrido[3,4-b]-pyridine antitumor compounds - Google Patents

Abstract

Camptothecin derivatives of formula (I> <IMAGE> wherein R is hydrogen, alkyl, alkenyl or phenyl; Q is hydrogen, halogen, cyano, 5-tetrazolo, -COOR<3>, -CONR<4> R<5>, -C(NH2)=NR<6>, -CH=NNH2, -(CH2)nR<7>, -CH=CH(CH2)nR<7> or -C=C(CH2)nR<7> wherein n is 0, 1, 2 or 3; R<3> is hydrogen or alkyl; R<4> and R<5> independently represent hydrogen, alkyl, aminoalkyl or dialkylaminoalkyl; R<6> is hydrogen, alkyl, hydroxy, alkoxy or -COOCH2NHCOO<t>Bu; R<7> is hydrogen, hydroxy, -NR<1>R<2>, -NHCOR<8> or a nitrogen heterocycle of formula <IMAGE> wherein R<1> and R<2> independently represent hydrogen or alkyl; R<8> is alkyl or O-alkyl; Y is O, S, NR<9>, CH2 or a direct linkage; R<9> is hydrogen or alkyl; T is hydrogen or when Q is halogen T may also represent halogen; and X is a free electron pair, oxygen or alkyl; and pharmaceutically acceptable salts thereof, are topoisomerase inhibitors useful in the treatment of cancer. Pyridines of formula (II> <IMAGE> wherein R* is methyl or ethyl Q<1> is Br and T is H or Br; and derivatives corresponding to formula (I) but with the E ring open are novel intermediates.

Description

PYRIDO13,4-b]-PYRIDINE ANTITUMOR COMPOUNDS The present invention relates to pyrido[3,4-b] pyridines. More particularly the invention relates to camptothecin derivatives which include a nitrogen atom at the 11 position on the A ring and are substituted at the 7 and 10 position as described herein; the invention also relates to the use of these compounds as topoisomerase inhibitors in the treatment of tumors and to methods of their preparation.

BACKGROUND OF THE INVENTION Camptothecin, a natural, cytotoxic alkaloid, is a topoisomerase I inhibitor and potent antitumor agent. It was first isolated from the leaves and bark of the Chinese plant, Camptotheca Acuminata, by Wall, et al. (J. Am Chem. Soc., 88 3888 (1966)).

As depicted, camptothecin is a fused ring system composed of a quinoline (A and B), fused to a pyrrolidine ring (C), fused to an alpha-pyridone ring (D) which in turn is fused to a lactone ring (E).

It has an asymmetric carbon at the 20 position making two enantiomeric forms possible. However, the natural occurring compound is found in the "S" configuration as shown above.

Cytotoxic agents are often employed to control or eradicate tumors i.e., they are chemotherapeutic agents. Camptothecin's cytotoxic activity is thought to be directly related to camptothecin's potency as a topoisomerase inhibitor. [For detailed explanations of the topoisomerase function see A. Lehninger, Principles of Biochemistry, 813, Worth Publishers, New York (1982); L. F. Liu, "DNA Topoisomerases," CRC Crifical Review in Biochemistry, 1-24, 15 (1983); and H. Vosberg, "DNA Topoisomerases: Enzymes that Control DNA Conformation," Current Topics in Microbiology and Immunology, 19, Springer-Verlag, Berlin (1985).] In particular, camptothecin has been shown to be effective in the treatment of leukemia (L-1210) and certain solid tumors in laboratory animals, e.g., see M. Potmesil, et al., DNA Topoisomerase in Cancer, Oxford Univ. Press (1991), Chem.Rev. 23, 385 (1973) and Cancer Treat. Rep., 60, 1007 (1967).

Unfortunately, in the clinic camptothecin's promise as an effective antitumor agent has not been completely fulfilled. In the art there are examples of modifications and derivatives of camptothecin prepared to improve its activity.

One approach which has been taken is to design derivatives of camptothecin having higher water solubility. Camptothecin is essentially insoluble in physiologically compatible, aqueous media, and must be modified to make it sufficiently soluble for parenteral administration, a preferred mode for antitumor treatment. It can be made soluble by forming its sodium salt, that is, by opening the lactone with sodium hydroxide (see F.M. Muggia, et al., Cancer Chemotherapy Reports, pt. 1, 56, No.4, 515 (1972)). However, M. C. Wani, et al., J. Med. Chem, 23, 554 (1980), reported that the alpha-hydroxy lactone moiety of ring E is an absolute requirement for antitumor activity.

Miyasaka, et al., U.S. Patent No. 4,399,282, and Chem. Pharm. Bull 39(10), 2574 (1991) discloses a group of camptothecin derivatives substituted at the 7 position with, inter alia, hydroxymethyl and alkoxymethyl and lower alkyl. More recently, Miyasaka, et al., in U.S. Patent No. 4,604,463, have claimed a series of 7-alkyl camptothecin derivatives with various substituents at the 10-position.

Further, Miyasaka, et. al. in U.S. patent No. 4,399,276 discloses camptothecin-7-aldehyde and certain related aldehyde derivatives such as acetals, oximes and hydrazones. More recently, Vishnuvajjala, et al., in U.S.

Patent No. 4,943,579, claimed a series of water-soluble camptothecin derivatives with substituents on the A ring as does Boehm, et al., European Patent Application 0 321 122 A2. Other examples of derivatives of camptothecin include Miyasaka, et al., U.S. Patent No. 4,473,692 and No.

4,545,880; and W. Kingsbury, et al., J. Med. Chem., 34, 98 (1991).

Additional approaches have been taken to design camptothecin derivatives which strongly bind to the topoisomerase-DNA complex. One modification which appears to enhance binding is to introduce electronegative atoms or substituents in the A ring. U.S. Patent 4,894,456 to Wall, et al. and J. Med.

Chem 1986, 29, 2358 discloses 10-aza-20(R,S)-camptothecin and 12-aza20(R,S)-camptothecin. Yaegashi, et al., U.S. Patent No. 5,061,800, have claimed several 7-alkyl camptothecin derivatives with the electronegative fluoride substituent at the 11-position that show potent antitumor activities in vitro.

We have now found 1 0-substituted-1 1 -aza analogs of camptothecin with good, topoisomerase I inhibitory activity in vitro.

SUMMARY OF THE INVENTION One aspect of the present invention is water-soluble camptothecin derivatives of formula (I),

wherein R is hydrogen, alkyl, alkenyl or phenyl; Q is hydrogen, halogen, cyano, 5-tetrazolo, -COOR3, -CONR4R5, -C(NH2)=NR6, -CH=NNH2, -(CH2)nR7, -CH=CH(CH2)nR7 or -C=C(CH2)nR7 wherein n is 0,1, 2 or 3; R3 is hydrogen or alkyl; R4 and R5 independently represent hydrogen, alkyl, aminoalkyl or dialkylaminoalkyl; R6 is hydrogen, alkyl, hydroxy, alkoxy or -COOCH2NHCOOtBu; R7 is hydrogen, hydroxy, -NR1 R2, -NHCOR8 or a nitrogen heterocycle of formula

wherein R1 and R2 independently represent hydrogen or alkyl; R8 is alkyl or O-alkyl; Y is O, S, NR9, CH2 or a direct linkage; R9 is hydrogen or alkyl;T is hydrogen or when Q is halogen T may also represent halogen; and X is a free electron pair, oxygen or alkyl; and pharmaceutically acceptable salts thereof.

Those skilled in the art will recognise that certain compounds of formula (I) exist as quaternary ions (e.g. when X is alkyl) or may be protonated at the N-ll position to form quaternary salts. Compounds wherein X is oxygen are N-oxides.

Pharmaceutically acceptable salts include, but are not limited to salts with inorganic acid counterions, such as chloride, sulfate, phosphate, diphosphate, bromide and nitrate, or salts with organic acid counterions such as acetate, malate, maleate, fumarate, tartrate, succinate, citrate, lactate, methanesulfonate, p-toluenesulfonate, palmoate, salicylate and stearate. Other acids such as oxalic, while not in themselves pharmaceutically acceptable, may be useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable salts.

The lactone ring, ring E, may be opened by alkali metal or alkaline-earth metal bases, for example sodium hydroxide or calcium hydroxide, to form alkali metal or alkaline-earth metal salts of the corresponding open E ring form of the compounds of formula (I). Because of its better solubility in water, the open E ring form may advantageously be purified by conventional recrystallization techniques. Accordingly, said open E ring form may then be used as an intermediate to form the compounds of formula (I), for example by treatment with acid, e.g., hydrochloric acid, and thereby produce a purified form of the compounds of formula (I).

As noted above, the camptothecin moiety has an asymmetric carbon atom at the 20 position making two enantiomeric forms, i.e., "R" and "S" configurations, possible. This invention includes both enantiomeric forms and any combinations of these forms. For simplicity, where no specific configuration at the 20 position is depicted in the structural formulas, it is to be understood that both enantiomeric forms and mixtures thereof are represented. Unless noted otherwise, the nomenclature convention, "(R,S)", denotes a racemic (approximately equal portion) mixture of the R and S enantiomers while "(R)" and "(S)" denote essentially optically pure R and S enantiomers respectively.

Also included in the invention are other forms of the compound of formula (I), such as solvates, hydrates, polymorphs and the like.

Another aspect of the invention is a method of inhibiting topoisomerase Type I in mammalian cells comprising administering to a patient a topoisomerase inhibiting amount of a compound of formula (I), and a method of treating a tumor in a mammal comprising administering to a mammal bearing a tumor, an effective antitumor amount of a compound of formula (I). A further aspect comprises pharmaceutical formulations containing a compound of formula (I) as an active ingredient. Methods for the preparation of the compounds of formula (I) and the associated novel chemical intermediates used in the synthesis, as taught wherein, are also within the scope of the present invention DETAILED DESCRIPTION OF THE INVENTION Compounds When R is phenyl, the phenyl group may be substituted at the meta or para positions.Representative substituents are alkyl, alkenyl and alkoxy wherein the substituent may contain 1 to 6 carbon atoms.

The term "alkyl" as used herein refers to straight chain, branched chain or cyclic alkyl groups which typically contain up to 6 carbon atoms. The term "alkenyl" as used herein refers to straight chain or branched chain 1-alkenyl groups having 2 to 7 carbon atoms. These definitions also apply to any moiety containing an alkyl or alkenyl. Preferred alkyl groups contain 1 to 3 carbon atoms, for example methyl, ethyl, propyl. Preferred alkenyl groups contain 2 to 4 carbon atoms, for example ethenyl, 1 -propenyl and 1 -butenyl.

Typically R may represent hydrogen or alkyl (e.g. methyl or ethyl).

Particular compounds of formula (I) are those wherein R represents methyl or ethyl and X represents a free electron pair.

In a preferred group of compounds of formula (I) Q is a substituent which yields a water solubilising salt especially, for example, an aminoalkyl, amidoximo or amidino group.

In one aspect the invention further provides a compound of formula (la)

wherein Ra is alkyl or phenyl; Qa is halogen, cyano, 5-tetrazolo, R1aR2aN-, R3aOOC-, R4aR5aNCO-, (H2N)C=NR6-, R7a-(C H2)na-CrC-, R7a-(CH2)naCH=CH-, R7a(cH2)na- where Tri a and R2a independently represent hydrogen or alkyl; R3a is hydrogen or alkyl; R4a and R5a independently represent hydrogen, alkyl, aminoalkyl or dialkylaminoalkyl; na is 1 to 3; R6a is hydrogen, alkyl, hydroxy, alkoxy, t-BuOCONHCH2COO-;R7a is hydrogen, hydroxy, RlaR2aN- or a nitrogen heterocycle of the formula

where Ya is O, S, Roan, CH2 or a direct linkage where R8a is hydrogen or alkyl; and Xa is a free electron pair; and when Qa is RlaR2aN-, R7a(CH2)na-, Xa may also represent 0 or Xa may represent alkyl such that N-i 1 is quaternized; and pharmaceutically acceptable salts thereof.

Specific compounds of formula (I) include: (S)-(-)-1 1 -Aza-i 0-carboxamidoxime-7-ethylcamptothecin, and pharmaceutically acceptable salts thereof.

Preparation of Compounds According to one general process (A) the compounds of formula (I) wherein Q is hydrogen or halogen and R is other than hydrogen may be prepared by reacting a compound of formula (II)

wherein Q1 is hydrogen or halogen, preferably bromine, T is hydrogen or halogen, preferably bromine, and R* is alkyl, alkenyl or phenyl, with a tricyclic ketone of formula (Ill)

The reaction is preferably carried out in the presence of an acid or base catalyst. The acid catalyst is preferably a mineral acid such as for example HCI, H2SO4, HNO3 and H3PO4 or an organic acid such as C18 alkanoic acids and C1 12 arylsulfonic acids, especially p-toluenesulfonic acid.The base catalyst is preferably an inorganic base such as for example sodium and potassium carbonate and sodium and potassium bicarbonate or an organic base such as a hindered base for example triethylamine and diisopropylamine.

The reaction may be carried out neat or in the presence of a polar or non-polar solvent. Preferred polar solvents are the C1 6 alcohols, ethers and dimethylformamide. Preferred non-polar solvents are branched or staight chained alkyl hydrocarbons having 4-10 carbon atoms and aromatic hydrocarbons having 6-20 carbon atoms, especially toluene. The reaction is generally conducted with heating at reflux.

The tricyclic ketone of formula (Ill) may be prepared according to the procedure of Wall, et al., U.S. Patent 4,894,456, at column 11, starting at line 30. It is apparent that the configuration of the asymmetric carbon of the compound of formula (III) will govern the configuration of the compounds of formula (I). The racemic compound of formula (III) can be resolved into either of its enantiomers by the method of Wani et al., in United States Patent 5,053,512, (hereinafter, "'512") incorporated herein by reference.

Compounds of formula (11) wherein Q1 is halogen may be prepared by reacting a compound of formula (lV)

with a halogenating agent,-for example a brominating agent such as pyrrolidone hydrotribromide, to give a mixture of pyridine derivatives (I IA), (lIB) and (V).

where Hal is halogen, preferably bromine.

Depending upon the choice of halogenating agent and the reaction conditions, the monohalide (IIA) or the dihalide (lIB) can be isolated chromatographically as the predominant product. Thus, for example, under the conditions used to prepare Intermediate 1, a 6:1:1 mixture of (IIA):(IIB):(V) was obtained whereas using excess brominating agent to prepare Intermediate 2 gave the dibromo derivative (IIB).

The Friedlander reaction (Process A) is a chemoselective reaction. If compound (IIB) and (V) are present with compound (I IA), compound (IIA) reacts to the exclusion of compounds (lIB) and (V). By separating the dihalide (IIB) from the other compounds, the reaction can be forced to yield the do halo derivative (Q = T = Hal).

Compounds of formula (II) wherein Q1 and T are both hydrogen may be prepared by reduction of a compound of formula (VI)

with a suitable reducing agent.

Compounds of formula (VI) may be prepared by oxidation of a compound of formula (all)

with a suitable oxidising agent.

Compounds of formula (VII) may be prepared by reaction of a compound of formula (VIII)

with an organometallic compound using methods well known to those skilled in the art. Typical organometallic compounds include methyl lithium and diethyl zinc. Compounds of formula (VII) wherein R* is phenyl may be prepared using a Grignard reagent.

According to a second general process (B) the compounds of formula (I) wherein Q is hydrogen or halogen and R is hydrogen may be prepared by reacting a compound of formula (III) with a compound of formula (IX)

wherein Q1 is hydrogen or halogen, preferably bromine. Suitable conditions are as described above for general process (A).

The compound of formula (IX) wherein Q1 and T are both hydrogen, 3-(3-amino4-picolylidene)-p-toluidine, is known and may be prepared by the methods taught by Baumgarten & Krieger, J.Am.Chem.Soc. (1955) 77, 2438. Other compounds of formula (IX) may be prepared by methods known to those skilled in the art.

According to another general process (C), a compound of formula (I) may be converted into another compound of formula (I) using conventional procedures.

Thus, for example compounds of formula (I) wherein Q is halogen, e.g. bromine may be converted to compounds of formula (I) wherein Q is other than halogen.

Thus, a compound of formula (I) wherein Q is halogen may be reacted with tributyltin cyanide in the presence of a palladium catalyst, to form the corresponding cyano derivative. This compound can be reduced by the method taught by Engbersen (J. Heterocyclic Chem, 1986, 23, 989) as shown in Examples 12 and 13 to afford the corresponding aminomethyl derivative. The aminomethyl derivative may be condensed with an aldehyde under reductive conditions to afford dialkylamines wherein Q is -CH2NR1R2 and R1 and R2 represent alkyl or phenyl, or it may be condensed with an an hydride under nonreductive conditions to yield a carboxamide wherein Q is -CH2NHCOR8 and R8 is alkyl or O-alkyl, etc. Compounds where Q is -CH2NHCOR8 may be oxidised, for example with mCPBA to afford 11-N-oxide derivatives.Oxidation at the nitrogen at the position has not been found to be a problem. Cleavage under acidic conditions, such as those taught in T. Green, Protective Groups in Organic Chemistry, Chap. 7, John Wiley, New York (1981), results in the formation of compounds of formula (I) wherein Q is -CH2NH2.

Alternatively compounds of formula (I) wherein Q is CN may be treated with hydroxylamine hydrochloride, as shown in Examples 9 and 10, to form the corresponding 1 0-carboxamidoxime. Reduction of the amidoxime under conditions such as those taught by Fuji (Heterocycles, 1986, 24, 2449-54) and shown in Example 11 affords 10-amidines. Treatment of the nitrile with tributyltin azide with heating affords the corresponding tetrazole. Hydrolysis of the nitrile in a polar protic solvent yields the 10-carboxamido derivative.

Alternatively, the amidoxime derivative may be treated with a mixed an hydride of a carboxylic acid such as N-tert-butyloxyglycine in a polar aprotic solvent such as 1,4-dioxane to give the corresponding O-acylated derivative as shown in Example 39.

Bromide substitution reactions with alkynes using methods taught by Kalinin (Synthesis, 1992, - 5, 413). afford derivatives of formula (I) wherein Q is -C-C (C H2)nR7. Reduction with hydrogen affords the corresponding alkane derivatives. This reaction proceeds through the corresponding alkene derivative which can also be isolated. Hydroxy or amine substituted alkynes can be used in the reaction to yield the corresponding hydroxy or amino alkyne, alkene or alkyl derivatives.

Alternatively compounds of formula (I) wherein Q is halogen e.g. bromide may be heated under a CO atmosphere in a solvent mixture containing either an alcohol or an amine or a diaminoalkane such as N,N-dimethylethylenediamine, using the method taught by Ozawa (J. Am Chem. Soc. 1985, 107, 3235) to give the corresponding ester or amide of formula (I) wherein Q is COOR3 or CONR4R5. Hydrolysis of the ester or amide using mineral acids affords the carboxylic acid. Subjecting the acid to conditions taught by Ninomiya (Tetrahedron, 1974, 30, 2151) affords 10-amino substituted derivatives of formula (I) wherein Q is -NH2. These reactions are illustrated in Examples 19, 20 and 21.

Alternatively compounds of formula (I) wherein Q is halogen e.g. bromine may be reacted with vinyltributyltin according to the method taught by Stille (Agnew.

Chem. Int. Ed. Engl. 1986, 25, 508) to afford the 10-vinyl substituted derivative.

Oxidation with osmium tetraoxide and sodium periodate yields the aldehyde intermediate and reduction with a bulky hydride such as lithium tri tertbutyloxyaluminum hydride affords the 10-hydroxymethyl derivatives of formula (I) as shown in Example 35. A 10-substituted hydrazone analog such as that of Example 38 can be obtained from the 10-vinyl substituted derivative by oxidative cleavage with a reagent such as sodium periodate and catalytic osmium tetroxide to afford the intermediate 10-carboxaldehyde which when treated with a hydrazine derivative such as Girard's Reagent T affords the product.

Compounds of formula (I) wherein X is a free electron pair may be oxidised to give compounds of formula (I) wherein X is oxygen. The reaction may conveniently be conducted using m-chloroperbenzoic acid as the oxidising agent. Conducting the reaction at reduced temperatures to discourage reaction at the 1-position may be desirable but is not necessary in many cases.

Alternatively compounds of formula (I) wherein X is a free electron pair may be reacted with an alkyliodide to give the corresponding compound of formula (I) wherein X is alkyl or alkyliodide.

According to another general process (D), a compound of formula (I) according to the invention, or a salt thereof may be prepared by subjecting a protected derivative of a compound of formula (I) or a salt thereof to reaction to remove the protecting group or groups.

Thus, at an earlier stage in the preparation of a compound of formula (I) or a salt thereof it may have been necessary and/or desirable to protect one or more sensitive groups in the molecule to prevent undesirable side reactions.

The protecting groups used in the preparation of compounds of formula (I) may be used in conventional manner. See for example 'Protective Groups in Organic Chemistry' Ed.J.F.W. McOmie (Plenum Press 1973) or 'Protective Groups in Organic Synthesis' by Theodora W Greene (John Wiley and Sons 1981).

Conventional amino protecting groups may include for example aralkyl groups, such as benzyl, diphenylmethyl or triphenylmethyl groups; and acyl groups such as N-benzyloxycarbonyl or t-butoxycarbonyl. Thus, compounds of general formula (I) wherein one or more of the groups R1 and R2 represent hydrogen may be prepared by deprotection of a corresponding protected compound.

Hydroxy groups may be protected, for example, by aralkyl groups, such as benzyl, diphenylmethyl or triphenylmethyl groups, acyl groups, such as acetyl, silicon protecting groups, such as trimethylsilyl or t-butyl dimethyisilyl groups, or as tetrahydropyran derivatives.

Removal of any protecting groups present may be achieved by conventional procedures. Thus an aralkyl group such as benzyl, may be cleaved by hydrogenolysis in the presence of a catalyst (e.g. palladium on charcoal); an acyl group such as N-benzyloxycarbonyl may be removed by hydrolysis with, for example, hydrogen bromide in acetic acid or by reduction, for example by catalytic hydrogenation; silicon protecting groups may be removed, for example, by treatment with fluoride ion or by hydrolysis under acidic conditions; tetrahydropyran groups may be cleaved by hydrolysis under acidic conditions.

As will be appreciated, in any of the general processes (A) to (C) described above it may be desirable or even necessary to protect any sensitive groups in the molecule as just described. Thus, a reaction step involving deprotection of a protected derivative of general formula (I) or a salt thereof may be carried out subsequent to any of the above described processes (A) to (C).

Thus, according to a further aspect of the invention, the following reactions may, if necessary and/or desired be carried out in any appropriate sequence subsequent to any of the processes (A) to (C): (i) removal of any protecting groups; and (ii) conversion of a compound of formula (I) or a salt thereof into a pharmaceutically acceptable salt or solvate thereof.

Where it is desired to isolate a compound of the invention as a salt, for example as an acid addition salt, this may be achieved by treating the free base of general formula (I) with an appropriate acid, preferably with an equivalent amount, or with creatinine sulphate in a suitable solvent (e.g. aqueous ethanol).

As well as being employed as the last main step in the preparative sequence, the general methods indicated above for the preparation of the compounds of the invention may also be used for the introduction of the desired groups at an intermediate stage in the preparation of the required compound. It should therefore be appreciated that in such multi-stage processes, the sequence of reactions should be chosen in order that the reaction conditions do not affect groups present in the molecule which are desired in the final product.

Typically, biological activity of the compounds of formula (I) resides in the S enantiomer, and the R enantiomer has little or no activity. Thus, the S enantiomer of a compound of formula (I) is generally preferred over a mixture of R and S such as the racemic mixture. However, if the R enantiomer were desired, e.g., for control studies or synthesis of other compounds1 it could be conveniently prepared by the procedure above using the R enantiomer of the compound of formula (VII) prepared according to the teachings of '512.

A compound of formula (l) may be purified by conventional methods of the art, e.g., chromatography, distillation or crystallization.

Cleavable Complex in vitro Assay The relative topoisomerase Type I inhibitory activity of the compounds of formula (I) was determined by cleavable complex in vitro assay. This assay performed according to the method described in Hsiang, Y. et al., J. Biol.

Chem., 260:14873- 14878 (1985), correlates well with in vivo anti-tumor activity of topoisomerase inhibitors in animal models of cancer, e.g., camptothecin and its analogs. See Hsiang et al., Cancer Research, 49:4385-4389 (1989) and Jaxel et al., Cancer Research, 49:1465-1469 (1989).

The compounds of Examples 5 and 41 exhibited observable topoisomerase Type I inhibitory activity (IC50) at concentrations greater than 2000nM (weakly to moderately active), the compounds of Examples 3, 18, 21, 22, 23, 25, 26, 28, 36 and 43 at concentrations greater than 1000nM, the compounds of Examples 16, 17, 24, 27, 31, 34 and 37 at concentrations greater than 500nM and all the remaining exemplified compounds at concentrations of less than 500nM (very active). The compound of Example 19 was not tested. The term "IC50" means the concentration of a compound of formula (I) at which 50% of the DNA substrate has been captured by topoisomerase I.

The compounds of formula (I) are active against a wide spectrum of mammaiian (including human) tumors and cancerous growths such as cancers of the oral cavity and pharynx (lip, tongue, mouth, pharynx), esophagus, stomach, small intestine, large intestine, rectum, liver and biliary passages, pancreas, larynx, lung (including non-small cell), bone, connective tissue, skin, colon, breast, cervix uteri, corpus endometrium, ovary, prostate, testis, bladder, kidney and other urinary tissues, eye, brain and central nervous system, thyroid and other endocrine glands, leukemias (lymphocytic, granulocytic, monocytic), Hodgkin's disease, non-Hodgkin's lymphomas, multiple myeloma, etc. Herein the terms "tumor", "cancer" and "cancerous growths" are used synonymously.

The amount of compound of formula (I) required to be effective as an antitumor agent will, of course, vary with the individual mammal being treated and is ultimately at the discretion of the. medical or veterinary practitioner. - The factors to be considered include the condition being treated, the route of administration, the nature of the formulation, the mammal's body weight, surface area, age and general condition, and the particular compound to be administered. However, a suitable effective antitumor dose is in the range of about 0.1 to about 200 mg/kg body weight per day, preferably in the range of about 1 to about 100 mg/kg per day. The total daily dose may be given as a single dose, multiple doses, e.g., two to six times per day, or by intravenous infusion for a selected duration.

Dosages above or below the range cited above are within the scope of the present invention and may be administered to the individual patient if desired and necessary.

For example, for a 75 kg mammal, a dose range would be about 75 to about 7500 mg per day, and a typical dose would be about 800 mg per day. If discrete multiple doses are indicated, treatment might typically be 200 mg of a compound of formula (I) given 4 times per day.

Formulations Formulations of the present invention, for medical use, comprise an active compound, i.e., a compound of formula (I), together with an acceptable carrier thereof and optionally other therapeutically active ingredients. The carrier must be pharmaceutically acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

The present invention, therefore, further provides a pharmaceutical formulation comprising a compound of formula (I) together with a pharmaceutically acceptable carrier thereof.

The formulations include those suitable for oral, rectal, topical or parenteral (including subcutaneous, intramuscular and intravenous) administration.

Preferred are those suitable for oral or parenteral administration.

The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the active compound into association with a carrier which constitutes one or: more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing the active compound into association with a liquid carrier or a finely divided solid carrier and then, if necessary, shaping the product into desired unit dosage form.

Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets, tablets or lozenges, each containing a predetermined amount of the active compound; as a powder or granules; or a suspension or solution in an aqueous liquid or non-aqueous liquid, e.g., a syrup, an elixir, an emulsion or a draught.

A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active compound in a free-flowing form, e.g., a powder or granules, optionally mixed with accessory ingredients, e.g., binders, lubricants, inert diluents, surface active or dispersing agents. Molded tablets may be made by molding in a suitable machine, a mixture of the powdered active compound with any suitable carrier.

A syrup or suspension may be made by adding the active compound to a concentrated, aqueous solution of a sugar, e.g., sucrose, to which may also be added any accessory ingredients. Such accessory ingredient(s) may include flavoring, an agent to retard crystallization of the sugar or an agent to increase the solubility of any other ingredient, e.g., as a polyhydric alcohol, for example, glycerol or sorbitol.

Formulations for rectal or vaginal administration may be presented as a suppository with a conventional carrier, e.g., cocoa butter or Witepsol S55 (trademark of Dynamite Nobel Chemical, Germany, for a suppository base).

For transdermal administration the compounds according to the invention may be formulated as creams, gels, ointments or lotions or as a transdermal patch.

Such compositions may for example be formulated with an aqueous or oily base with the addition of suitable thickening, gelling, emulsifying, stabilising, dispersing, suspending, and/or colouring agents.

Formulations suitable for parenteral administration conveniently comprise a sterile aqueous preparation of the active compound which is preferably isotonic with the blood of the recipient. Such formulations suitably comprise a solution or suspension of a pharmaceutically and pharmacologically acceptable acid addition salt of a compound of the formula (I) that is isotonic with the blood of the recipient. Thus, such formulations may conveniently contain distilled water, 5% dextrose in distilled water or saline and a pharmaceutically and pharmacologically acceptable acid addition salt of a compound of the formula (I) that has an appropriate solubility in these solvents, for example the hydrochloride.Useful formulations also comprise concentrated solutions or solids containing the compound of formula (I) which upon dilution with an appropriate solvent give a solution suitable for parenteral administration above.

In addition to the aforementioned ingredients, the formulations of this invention may further include one or more optional accessory ingredient(s) utilized in the art of pharmaceutical formulations, e.g., diluents, buffers, flavoring agents, binders, surface active agents, thickeners, lubricants, suspending agents, preservatives (including antioxidants) and the like.

EXAMPLES The following examples illustrate aspects of this invention but should not be construed as limitations. The symbols and conventions used in these examples are consistent with those used in the contemporary chemical literature, for example, the Journal of the American Chemical Society. As used here in the term "room temperature" means about 25"C.

Intermediate 1 5-Amino-2-bromo-4-(1 -oxoethyl)pyridine In a small flask was dissolved 3-amino-4-(1-oxoethyl)pyridine (214 mg, 1.57 mmol) in anhydrous THF (43 mL), and NaHCO3 (264 mg, 3.24 mmol) was added. The stirred slurry was treated by the dropwise addition of pyrrolidone hydrotribromide in THF (701 mg in 10 mL), which was added via pipette.

Additional pyrrolidone hydrotribromide (77 mg in 3 mL THF) was added, after 10 min. and the yellow slurry was allowed to stir at ambient temperature for 14 h.

Without concentration, the reaction mixture was passed directly through a plug of silica, eluting with 100% ethyl acetate followed by 10:1 ethyl acetate/triethylamine. The resulting clear yellow solution was concentrated with a rotary evaporator, and the semi-solid residue was purified by radial chromatography (3:1 hexane/ethyl acetate eluant) to afford 214 mg (63% yield) of the product obtained as a 6:1 mixture of regioisomers, as judged by 1H NMR analysis. 1H NMR 6 (300 MHz, CDCl3) (minor regioisomer in parenthesis): 2.60 (s, 3H), (2.62) (7.45) 6.10 (bs, 2H), (7.75) 7.6 (s, 1 H), 7.98 (s, 1 H). Low resolution mass spectroscopy shows parent ion (M+1) at 215 (calcd 215).

Intermediate 2 4-Amino-2 .6-dibromo-3-(1 -oxoethyl)pyridine To a solution of 4-amino-3-(i-oxoethyl)pyridine (85 mg, 0.625 mmol) in THF (5.0 mL) at ambient temperature was added in one portion pyrrolidone hydrotribromide (620 mg, 1.25 mmol). The yellow-orange slurry was allowed to stir for 10 min, and was quenched by the addition of saturated aqueous NaHCO3 (20 mL). The mixture was extracted with ethyl acetate (3 times 20 mL), and the combined organic layers were dried over Na2SO4, filtered and concentrated to give an orange semi-solid residue.Purification by radial chromatography (1:1 hexane/ethyl acetate) afforded 125 mg (83% yield) of the product dibromide as a yellow oil that solidified upon standing. 1H NMR (300 MHz, CDC13): 6 2.60 (s, 3H), 6.70 (bs, 2H), 7.61 (s, 1H). Low resolution mass spectroscopy shows parent ion (M+1) at 295 (calcd 295).

Intermediate 3 5-Amino-2-bromo-Q-( 1 -oxonropyl )pvn.dine To a stirring solution of 3-amino-4-(1-oxopropyl)pyridine (180 mg, 1.20 mmol) in anhydrous THF (45 mL) at ambient temperature was added NaHCO3 (202 mg, 2.40 mmol) followed by pyrrolidone hydrotribromide (595 mg, 1.20 mmol). The bright orange-yellow slurry was stirred at ambient temperature for 4h. Without concentration, the reaction mixture was passed through a short silica gel column, washing with ethyl acetate followed by 5% triethylamine in ethyl acetate.The crude prqduct, which eluted with the 100% ethyl acetate fraction, was obtained by concentration and silica gel chromatography (2:1 hexanes/ethyl acetate eluant) to afford 183 mg (67% yield) of a yellow semi-solid which analysis by 1H NMR spectroscopy showed was a 6:1 mixture of 5-amino:3amino isomers. 1H NMR (300 MHz, CDC13) (major isomer): 5 1.20 (t, 3H, J=6.9), 2.96 (q, 2H, J=6.9), 6.10 (bs, 2H), 7.65 (s, 1H), 7.98 (s, 1H). (Minor isomer): delta 1.21 (t, 3H, J=7.2), 3.00 (, 2H, J=7.2), 6.75 (bs, 2H), 7.49 (d, 1H, J=5.4), 7.71 (d, 1 H, J=5.4). Low resolution mass spectroscopy shows parent ion (M+1) at 229 (calcd 229).

Example 1 (S(-1 1 -Azacamptothecin A round-bottomed flask was charged with (S)-(-)-tricyclic ketone (382 mg, 1.45 mmol) and 3-(3-amino-4-picolylidene)-p-toluidine (J.Am.Chem.Soc. 1955, 77, 2438) (257 mg, 1.21 mmol) and anhydrous toluene (25 mL). A condenser and Dean-Stark trap with molecular sieves was attached, and the mixture was heated at reflux for a period of 30 min. The reaction mixture was allowed to cool to just below reflux, and p-toluenesulfonic acid (10 mg, 0.053 mmol) was added.

The mixture was heated at reflux for 18 h. The dark mixture was allowed to cool to room temperature, and the volatiles were removed with a rotary evaporator.

The residue was purified by silica gel chromatography (ethyl acetate followed by 6:5:1 ethyl acetate/chloroform/methanol elution) to afford 115.4 mg of the product (27% yield) as a tan-colored solid, mp 200 "C (dec.). Nominal Mass Spectrum M+1: 350.0 (calcd. 350.3) Example 2 (S)-(-)-1 1 -Aza-1 0-bromo-7-methylcamptothecin A round-bottomed flask was charged with 5-amino-2-bromo-4-(1 - oxoethyl)pyridine (82.2 mg, 0.382 mmol, contaminated with 20% of the 3-amino2-bromo isomer) and (S)-(-)-tricyclic ketone (105 mg, 0.40 mmol). Anhydrous toluene (4.0 mL) was added, and the mixture was brought to gentle reflux for 10 min. The mixture was allowed to cool to just below reflux, and p-toluenesulfonic acid (4.5 mg,-0.024 mmol) was added.The mixture was heated at reflux for 20 h, and allowed to cool to ambient temperature. The dark mixture was concentrated with a rotary evaporator, and the residue was triturated with 5:1 chloroform/methanol to afford 73.9 mg of the product as a pale tan solid, mp 274 "C (d). The mother liquor obtained from the trituration was concentrated to leave a solid residue which was further triturated as described above to afford 53.9 mg of additional product. (78% yield). 1H NMR (300 MHz, DMSO-d6): 6 0.90 (t, 3H, J=7), 1.85 (q, 2H, J=7), 2.79 (s, 3H), 5.38 (s,2H), 5.43 (s, 2H), 6.59 (s, 1 H), 7.38 (s, 1 HO, 8.45 (s, ,1 H), 9.37 (s, 1 H). Anal. Calcd for C20H16N304Br7/8H20: C, 52.45, H, 3.91, N, 9.17. Found: C, 52.70, H, 3.87, N, 9.22.Low resolution mass spectrometry shows parent ion (M+1) at 442.0 (calcd 442).

Example 3 (S)-(-)-1 1 -Azacamptothecin-1 1-N-Oxide: A round-bottomed flask was charged with (S)-(-)-i 1 -azacamptothecin (115 mg, 0.33 mmol) prepared as in Example 1 and m-chloroperbenzoic acid (m-CPBA) (50-60%, 143, mg, 0.41-50 mmol). The mixture was dissolved in CH2C12 (50 mL), and the solution was allowed to stir at ambient temperature for 15 h.

Additional m-CPBA (17 mg) was added, and the reaction mixture was allowed to stir for an additional 2 h. The mixture was added to water (20 ml) and extracted with 5:1 CHClg/isopropanol (2 times 20 mL). The combined organic layers were dried over an hydros Na2SO4, filtered and concentrated to afford the crude product. Purification by silica gel chromatography (6:5:1 ethyl acetate/ chloroform/methanol followed by 5:1 chloroform/methanol) afforded 119 mg of the product (99% yield) as a bright yellow solid, mp 215 OC (dec).Nominal Mass Spectrum (M+1): 366 (Calcd. 366.2) Example4 (S)-(-)-1 1 -Aza-1 0.1 2-dibro mo-7-methylcamptothecin A mixture of 4-amino-2,6-dibromo-3-(1-oxoethyl)pyridine (30 mg, 0.102 mmol) and (S)-(-)-tricyclic ketone (37 mg, 0.142 mmol) was taken up in anhydrous toluene (1.5 mL). The mixture, which bewe homogenous upon warming, was heated at reflux for 1d min. The solution was allowed to cool to just below reflux, and catalytic p-toluenesulfonic add monohydrate (5 mg) was added. The mixture was heated at reflux for 14 h, and allowed to cool to ambient temperature.The mixture was concentrated with a rotary evaporator, and the residue was dissolved in a minimum amount of 5:1 CHCI3/methanol and purified by radial chromatography (ethyl acetate followed by 5:1 CHCI3/methanol eluant) to afford 18 mg (34% yield) of the title compound as a tan solid, mp 200"C (d).

1H NMR (300 MHz, DMSO-d6):. 60.85 (t, 3H, J=7), 1.80-1.95 (m, 2H), 2.80 (s, 3H), 5.38 (s, 2H), 5.45 (s, 2H), 6.61 (s, 1H), 7.38 (s, 1 H), 8.47 (s, 1 H). Low resolution mass spectroscopy shows parent ion (M+1) at 521.7 (calcd 522).

Example 5 (R .S)-1 1 -Azacamptothein-1 1-N-methyl iodide A small round-bottomed flask was charged with 11-azacamptothean (8.5 mg, 0.024 mmmol) prepared as in Example 44 below and 1:1 CHCI3/methanol (1.0 mL). The mixture was treated with iodomethane (1.0 mL). The mixture was stirred at room temperature for 2.5 days at 40"C for 16 h. Thin layer chromatography (5:1 CHClg/methanol eluant, Whatman silica gel 60A) shows formation of a baseline UV-active (254 nm) spot.The volatiles were removed with a rotary evaporator to afford a tan solid residue. 1 H NMR (300 MHz, DMSO-d6): delta 0.90 (t, 3H, J=7), 1.85-2.00 (m, 2H), 4.60 (s, 3H), 5.42 (s, 2H), 5.44 (s, 2H), 7.44 (s, 1 H), 8.75 (d, 1 H, J=5), 8.95 (d, 1 H, J=5), 9.02 (s, 1 H), 10.25 (s, 1 H). Nominal Mass Spectrum (MH+1): 364 (calcd. 364.2).

Example 6 S)-(-)-11-Aza-10-bromo-7-ethylcamptothecin A mixture of 5-amino-2-bromo-4-(1-oxopropyl)pyridine (220 mg, 0.96 mmol), (S) (-)-tricyclic ketone (259 mg, 0.98 mmol), and anhydrous toluene (7.0 mL) was heated at reflux for a 10 min. The solution was allowed to cool to just below reflux, and catalytic p-toluenesulfonic acid (10 mg) was added.The mixture was heated at reflux for 15h, The dark brown reaction mixture was allowed to cool to ambient temperature, and the solid predpitate was.collected by suction filtration and washed with methyl acetate several times to afford 327 mg (75% yiëld) of the product as a yellow-brown solid, mp 273-275 C. 1H NMR (300 MHz, DMSOd6):: 60.85(t, 3H, J=7.2), 1.26 (t, 3H, J=7.2), 1.78-1.90 (m, 2H), 3.18-3.25 (m, 2H), 5.37 (s, 2H), 5.43 (s, 2H), 6.55 (s, tH), 7.36 (s, 1 H), 8.45 (s, 1 H), 9.34 (s, 1 H). Low resolution mass spectroscopy shows parent ion (M+1) at 456.1 (calcd 456). Anal. Calcd for C21H18N304Br.3/4 H2O: C, 54.74, H, 4.05; N, 9.12.

Found: C, 54.63; H, 4.00, N, 9.07.

Example7 (S)-(-)-11 -Aza-I OcyanoJ-methylcamptcthec1n A dry N2-flushed flask equipped with a stirring bar was charged with tributyltin cyanide (488 mg, 1.54 mmol) and tetrakis (triphenylphosphine) palladium (48 mg, 0.042 mmol), and anhydrous 1 ,2-dichloroethane (32 mL). The mixture was heated at a gentle reflux in an oil bath (bath temperature = 100 C) for 45 min.

The mixture was allowed to cool to just below reflux, (S)-(-)-l l-aza-l0-bromo-7- methylcamptothecin (340 mg, 0.769 mmol) was added. The mixture was heated at a general reflux for 15h. Additional palladium catalyst (10 mg) was added, and the mixture was heated at reflux for another 8h. The dark brown mixture was allowed to cool to ambient temperature, was concentrated to ca. 50% volume, and allowed to stand at 5 C for 12h. The product (215.4 mg) was collected as a greenish yellow precipitate by suction filtration and drying in a vacuum oven.The filtrate was concentrated and the residue was purified by silica gel chromatography (eluting with 100% ethyl acetate followed by 6:5:1 ethyl acetate/chloroform/methanol) to afford 64.3 mg of additional product, mp 293 C (d). 1H NMR (300 MHz, DMSO-d6) 8 0.87 (t, 3H, J=7.3), 1.90 (m, 2H), 2.85 (s, 3H), 5.38 (s, 2H), 5.43 (s, 2H), 6.60 (s, 1 H), 7.40 (s, 1 H), 9.00 (s, 1 H), 9.60 (s, 1H). Anal. Calcd for C21 H16N4O4.0.5CH3OH.0.35CHCl3: C, 58.82; H, 4.15; N, 12.56. Found: C, 58.73; H, 4.19; N, 12.34. Low resolution mass spectrometry shows parent ion (M+1) at 389.2 (calcd 389).

Example 8 (S)^ -11-Aza-10 cyano-7-ethylcamptothecin The procedure used was the same as Example 7, substituting the (S-)-(-)-1 1- aza-10-bromo-7-ethyl derivative (383 mg, 0.839 mmol) for the corresponding 7methyl compound, using 539 mg (1.71 mmol) of tributyltin cyanide, 58 mg (0.05 mmol) of tetrakis (triphyenylphosphine) palladium, and 35 mL an hydros 1,2dichloroethane. The reaction was allowed to proceed for 26h. Following partial concentration of the reaction mixture and cooling at 1000 overnight, 134 mg of product was obtained as a precipitate by suction filtration, mp 160 C (d).An additional 254 (388 mg total, 100% yield) was obtained by radial chromatography of the concentrated filtrate. 1H NMR (300 MHz, DMSC-d6): 6 0.85 (t, 3H, J=7), 1.28 (t, 3H, J=7), 1.84 (m, 2H), 5.42 (s, 2H), 5.45 (s, 2H), 6.59 (s, 1H), 7.40 (s, 1H), 9.02 (s, 1H), 9.59 (s, 1H). =1 Calcd for C22H18N4 6: C, 65.20, H, 4.50, N, 13.50. Found: C, 65.15, H, 4.63, N, 13.27.

Example9 (S)-(-)-i 1 -Aza-1 Scarboxamidoxime-7-methylcamptothean A small, round-bottomed flask was charged with (S)-(-)-1 1 -aza-1 0-cyano- 7-methylcamptothecin (16.3 mg, 0.042 mmol), ethyl acetate (3.0 mL), and H2O (1.0 mL). The mixture was stirred rapidly, and reacted with hydroxylamine hydrochloride (95 mg, 1.37 mmol) and Na2CO3 (64 mg, 0.52 mmol). The slurry was stirred at ambient temperature for 16h, then heated at reflux for 2h. Reflux was discontinued, and to the hot mixture was added glacial acetic acid (0.5 mL).

The mixture was stirred for 5 min, and the volatiles were removed with a rotary evaporator to afford a residue that was taken up in a small amount of water, and the solids were collected by suction filtration to afford, after drying, 16.8 mg (95% yield) of the product as a green solid, mp 260"C (d). 1H NMR (300 MHz, DMSOd6): 60.87(t, 3H, J=7), 1.88 (m, 2H), 2.78 (s, 3H), 5.36 (s, 2H), 5.44 (s, 2H), 6.06 (s, 2H), 6.55 (s, 1 H), 7.37 (s, 1 H), 8.49 (s, 1 H), 9.51 (s, 1 H), 9.99 (s, 1H). Low resolution mass spectrometry shows parent ion (M+1) at 422.2 (calcd 422).

Example 10 (S)-(-)-1 I -Aza-1 0-carboxamidoxime-7-ethylcamptothecin The procedure used was the same as Example 9 except (S)-(-)-1 1 -aza-1 0- cyano-7-ethylcamptothecin (238.8 mg, 0.593 mmol) and 1.39 g (20.0 mmol) of hydroxylamine hydrochloride were used. The reaction was carried out in 43 mL of ethyl acetate and 15 mL water.The same workup as Example 9 afforded 191.8 mg (74%) of the product as a yellowwgreen solid, mp 260"C. 1H NMR (300 MHz, DMSO-d6): 60.87(t, 3H, J=7), 1.31 (t, 3H, J-7), 1.86 (m, 2H), 3.24 (q, 2H, J=7), 5.39 (s, 2H), 5.44 (s, 2H), 6.06 (s, 2H), 6.56 (s, 1 H), 7.37 (s, I H), 8.51 (s, 1 H), 9.52 (s, 1 H), 10.02 (s, 1 H). Anal. Calcd for C22H2ON4O5.4CHCl3.4H2O: C, 56.38; H, 4.52; N, 11.74. Found: C, 56.58; H, 4.77; N, 11.38. Low resolution mass spectrometry shows parent ion (M+1) at 436.2 (calcd 436).

Example 11 (S)-(-)-i -11-aza-10-amidino-7-ethylcamptothean trifluoroacetic acid salt To a solution of (S)-(-)-1 1 -aza-1 0carboxamidoxime-7-ethyIcamptothecin (12.0 mg, 0.028 mmol) in 1.0 N HCI (3.0 mL) was added Raney nickel (73 mg, 50% aqueous). The mixture was stirred vigorously under 1 atm H2 for 18h. The mixture was filtered through a pad of celite, and the solvent was removed with a rotary evaporator to afford a greenish residue. Purification by reverse phase HPLC (Rainin Dynamax 60A column, eluting with 98:20:5:2 water/acetonitrile/THF/TFA) afforded, after lyophylization of the most intense UV active fraction, 3.0 mg (20% yield) of the product as a yellow powder, mp 250"C.

1H NMR (300 MHz, DMSO-d6): a 0.86 (t, 3H, J=7.3), 1.34 (t, 3H, J=7.3), 3.32 (q, 2H, J=7.3), 5.45 (s, 2H), 5.46 (s, 2H), 6.60 (s, 1 H), 7.43 (S, 1 H), 9.12 (s, 1 H), 9.34 (s, 2H), 9.67 (s, 1H), 9.76 (s, 2H). Low resolution mass spectrometry shows parent ion (M+1): 420.1 (calcd 420).

Example 12 (S)-(-)- 1 0-Aminomethyl- 11 -aza-7-methylcamptotheci n trifluoroacetic acid salt A mixture of 1 1-aza-10-cyano-7-methylcamptothecin (100.7 mg., 0.259 mmol) and 10% palladium on carbon (77 mg) in glacial acetic acid (160 mL) was stirred rapidly under 1 atm H2 for 4h. The mixture was filtered through a pad of celite, and concentrated with a rotary evaporator.The residue was purified by reverse phase HPLC (Rainin Dynamax 60A column, eluting with 9820:5:2 water/acetonitriletrHF/TFA) to afford, after lyophylization of the most intense UV action fraction, 107 mg of the product as a bright yellow lyophylate (81% yield), mp 230"C (d). 1H NMR (300 MHz, DMSO-d6): 8 0.87 (t, 3H, J=7), 1.87 (m, 2H), 2.80 (s, 3H), 4.42 (s, 2H), 5.37 (s, 2H), 5.45 (s, 2H), 6.56 (s, 1 H), 7.37 (s, 1 H), 8.30 (s, 1H), 9.59 (s,1 H). Anal. Calcd for C21 H20N4O4.2TFA.1 .5H2O: C, 46.37; H, 3.89; N; 8.65. Found: C, 46.50; H, 3.77; N, 8.62. Low resolution mass spectrometry shows parent ion (M+1) at 393.2 (calcd 393).

Example 13 (S)-(-)- 10-Amino methyl- 11 -aza-7-ethylcam ptotheci n tnfluoroacetle aad salt The procedure of Example 12 was carried out using (S)-(-)-1 1 -aza-1 0-cyano-7- ethylcamptothecin (100 mg, 0.259 mmol) obtained as in Example 8 to afford 120 mg of the crude acetic acid salt.A sample of this material (12 mg) was purified by reverse phase HPLC as described above to afford 4.5 mg of the title compound after lyophylization, mp 16000(d). 1H NMR (300 MHz, DMSO-d6): 6 0.87 (t, 3H, J=7.5), 1.35 (t, 3H, J=7.5), 1.87 (m, 2H), 3.21 (q, 2H, J=7.5), 4.43 (d, 2H, J=6), 5.41 (s, 2H), 5.45 (s, 2H), 6.56 (bs, 1H), 7.37 (s, 1H), 8.32 (s, 1H), 8.41 (s, 1H), 9.60 (s, 1H). b. Calcd for C22H22N404.1.5TFA.1H20: C, 50.42; H, 4.32; N, 9.41. Found: C, 50.46; H, 4.55; N, 9.30. Low resolution mass spectrometry shows parent ion (M+1) at 407.11 (calcd 407).

Example 14 (S)-(-)- ii -Dimethylaminomethyl-11 -aza-7-ethylcamptothecin trifluororacetic acid A sample of the crude amine prepared in Example 13 (30 mg, 0.064 mmol) was taken up in acetonitrile (1.5 mL), glacial acetic acid (0.25 mL) and 37% aqueous formaldehyde (7.4 uL, 0.266 mmol) and the mixture was cooled to OOC. To the stirring slurry was added NaCNBH3 (7.0 mg, 0.111 mmal), and the reaction mixture was stirred for 30 min.The reaction mixture was concentrated with a rotary evaporator to afford a brown residue, which was purified by reverse phase HPLC as described above to afford, after lyophylization, 8.5 mg (24% yield) of a yellow powder. 1H NMR (300 MHz, DMSO-d6); 6 0.87 (t, 3H, J=7.2), 1.33 (t, 3H, J=7.5), 1.89 (m, 2H), 2.85 (s, 3H), 2.86 (s, 3H), 3.23 (q, J=7.5), 4.66 d, 2H, J=4.5), 5.42 (s, 2H), 5.45 (s, 2H), 6.59 (bs, 1 H), 7.39 (s, 1 H), 8.36 (s, 1 H), 9.62 (s, 1H). Low resolution mass spectrometry shows parent ion (M+1) at 434.9 (calcd 435).

Example 15 (S)-(-)- 11 -Aza-1 o-(N-2-dimethylaminoethyl)carboxamido-7-ethvlcamptothecin A high pressure Parr reaction vessel (bomb) was charged with a degassed mixture of (S)-(-)-1 1 -aza-1 0-bromo-7-ethylcamptothecin (10 mg, 0.022 mmol), (PPh3)4Pd (10 mg), and N,N'-dimethylethylenediamine (6 uL, 0.06 mmol) in ethanol (3.0 mL). The apparatus was evacuated, placed under CO gas (100 psi), and heated at 1000C for 20h while stirring.The reaction vessel was allowed to cool to ambient temperature, and the contents were removed and concentrated with a rotary evaporator to afford a residue which was purified by radial chromatography (ethyl acetate followed by 5:1 chloroform/methanol eluant) to afford 7 mg (54% yield) of the title compound, mp 153"C. 1H NMR (300 MHz, DMSO-d6): 6 0.86 (t, 3H, J=7.2), 1.32 (t, 3H, J=7.2), 1.86 (m, 2H), 2.85 (s, 3H), 2.87 (s, 3H), 3.25-3.55 (m. 4H), 3.70 (q, 2H, J=5.7), 5.43 (s, 2H), 5.45 (s, 2H), 6.58 (bs, H), 7.40) (s, iH), 8.74 (s,1 1H), 9.30 (bs, iH), 9.40 (t, 1 H, J=5.7), 9.60 (s, 1H). Anal.Calcd for C26H29N5O5.1.5H2O.1.5TFA: C, 50.51; H, 4.9; N, 10.16. Found: C, 50.50; H, 5.30; N, 10.55. Low resolution mass spectrometry shows parent ion (M+1) at 492.0 (calcd 492).

Example 16 (S)-(-)- 11 -Aza-10-(N-2-aminoethyl)carboxamido-7-ethylcametothean trifluoroacetic acid salt The procedure of Example 15 was employed with 10 mg (0.22 mmol) of (S-(-)-1 1 -aza-1 0-bromo-7-ethylcamptothedn, (PPh3)4Pd (8 mg), triethylamine (10 uL), and ethylenediamine (10 uL, 0.15 mmol). The solvent used in this reaction was dioxane (5 ml). The reaction was heated at 1000C under 80 psi CO for 6h.Concentration of the reaction mixture afforded the crude product, which was purified by reverse phase HPLC (Dynamax column, eluting with 80:20 A/B eluant, A=2% aqueous TFA, B=4:1 acetonitrile/THF) to afford, after lyophylization, 5 mg (40% yield) of the product as a yellow powder, mp 165-1670 C. 1H NMR (300 MHz, DMSO-d6): 6 0.86 (t, 3H, J=6.9), 1.32 (t, 3H, J=7.5), 1.89 (m, 2H), 3.05 (q, 2H, J=7.5), 3.34 (m, 2H), 3.64 (m, 2H), 5.44 (s, 2H), 5.45 (s, 2H), 6.59 (bs, 1 H), 7.40 (s, 1 H), 7.78 (bs, 2H), 8.73 (s1 1 H), 9.33 (t, 1 H, J=6), 9.59 (s, 1H). Low resolution mass spectrometry shows parent ion (M+1) at 464.1 (calcd 464).

Example 17 (S)-(-)- 11 -Aza- 1 0-carboxy-7-ethylcamptothecin ethyl ester A Parr bomb was charged with a mixture of (S)-(-)-1 1 -aza-l 0-bromo-7- ethylcamptothecin (20 mg, 0.044 mmol), triethylamine (10 uL, 0.053 mmol), (PPh3)4Pd (15 mg) in degassed ethanol (8 mL). The mixture was heated at 100 C under 21 psi CO for 20h. The reaction mixture was allowed to cool to ambient temperature, and concentrated to afford the crude product.Purification by radial chromatography (ethyl acetate eluant) afforded 9 mg (46% yield) of the product as a yellow solid, mp 175 C (d). 1H NMR (300 MHz, DMSO-d6): 80.86 (t, 3H, J=7.2), 1.32 (t, 3H, J=7.5), 1.86 (m, 2H), 3.28 (q, 2H, J=7.5), 5.42 (s, 2H), 5.45 (s, 2H), 6.58 (bs, 1 H), 7.41 (s, 1 H), 8.78 (s, 1 H), 9.59 (s, 1 H). Anal. Calcld for C24H23N306.O.25H20: C, 63.22; H, 5.59; N, 9.25. Found: C, 63,41; H, 5.25; N, 9.14. Low resolution mass spectrometry shows parent ion (M+1) at 450.0 (calcd 450).

Example 18 (S)-(-)-1 1-Aza-1 0-carboxy-7-ethylcamptothean n A sample of (S)-(-)-1 1 -aza-1 0-ethycarboxylate-7-ethylcamptothecin (9 mg, 0.02 mmol) obtained as in Example 17 was taken up in methanol (1 mL), and 1.0 M aqueous LiOH (1.5 mL) was added dropwise. The reaction mixture was stirred for 30 min, and made just acidic by adding 1 M HCI dropwise.The mixture was concentrated with a rotary evaporator to leave a yellow residue, which was purified by reverse phase HPLC (Dynamax 60A column, 75:25 A/B, A=2% trifluoroacetic acid, B=4:1 acetonitrileflHF) to afford, after lyophylization, 4 mg (47% yield) of the product as a yellow powder, mp 165 C. 1H NMR (300 MHz, DMSO-d6): 60.86(t, 3H, J=7.2), 1.31 (t, 3H, J=7.5), 1.86 (m, 2H), 3.26 (q, 2H, J=7.5), 5.42 (s, 2H), 5.45 (s, 2H), 6.60 (bs, 1 H), 7.41 (s, 1 H), 8.77 (s, 1 H), 9.58 (s, 1H). Low resolution mass spectrometry shows parent ion (M+1) at 422.1 (calcd 422).

A larger scale reaction was also carried out using 235 mg (0.94 mmol) of ethylcarboxylate, which was taken up in 1:1:1 methanol.water:THF (6 mL). The slurry was treated with 1.0 M UOH (7my). The reaction mixture was acidified with 1 M HCI after 30 min, and concentrated to afford a residue that was triturated with water. The solid was collected by suction filtration and dried en vacuo to afford 190 mg{86% yield) of the product.

Example 19 (S)-(-)-i I -Aza-1 0-(N-tert-butyloxycarbonyl)aml no-7-ethylcamptothecin A slurry of (S)-(-)-1 1- a-10-carboxylic acid-7-ethylcamptothecin (30 mg, 0.071 mmol) obtained as in Example 18 in anhydrous dioxane (2.0 mL), and tert-butyl alcohol (1.0 mL) was prepared. The mixture was brought to reflux, and diphenylphosphoryl azide (39.2 mg, 0.143 mmol) and NaHCO3 (12 mg, 0.143 mmol) was added. The mixture was heated at reflux for 22h, allowed to cool to ambient temperature and concentrated to afford a brown solid residue.

Purification by radial chromatography afforded, after collecting the faster eluting UV active fractions and concentrating, 13 mg (37% yield) of the product. 1H NMR (300 MHz, DMSO-d6): 60.86(t, 3H, J-7), 1.32 (t, 3H, J=7), 1.53 (s, 9H), 1.86 (m, 2H), 3.15 (q, 2H, J=7), 5.37 (s, 2H), 5.42 (s, 2H), 6.53 (s, 1H), 7.31 (s, lH), 8.30 (s, 1H), 8.38 (s, iH), 9.26 (s, 1H), 10.20 (s, lah). Low resolution mass spectrometry shows parent ion (M+1) at 493.2 (calcd 493).

Example 20 (S)-(-)- 11 -Aza- 1 0-carboxamido-7-ethylcamptothecin Collecting, pooling and concentrating a slower eluting UV active band from the foregoing radial chromatography afforded 13 mg (44% yield) of the 10-carboxamide as a yellow solid, mp 155 C (d). 1H NMR (300 MHz, DMSO- d6): 60.86(t, 3H, J=7.2), 1.32 (t, 3H, J=7.2), 1.86 (m, 2H), 3.27 (q, 2H), 5.42 (s, 2H), 5.45 (s, 2H), 6.57 (s, 1 H), 7.40 (s, 1H), 7.89 (s, 1 H), 8.39 (s, 1 H), 8.73 (s, 1 H), 9.54 (s, 1 H). Low resolution mass spectrometry shows parent ion (M+1) at 421.1 (calcd421).

Example 21 (S)-(-)-1 Aza-10-amino-7-ethylcamptothean A solution of (S)-(-)-1 1 -Aza-1 0-(N-tert-butyloxycarbonyl)amino7-ethylcamptothecin (8.0 mg, 0.016 mmol) in CH2C12 (2.0 mL) obtained as in Example 19 was treated with TFA (0.5 mL) and the mixture was stirred at ambient temperature for 8h. The mixture was concentrated with a rotary evaporator and purified by radial chromatography to afford 1.3 mg (21 % yield) of the product as a bright yellow green solid, mp 158-160 C. 1H NMR (300 MHz, DMSO-d6): 3 0.85 (t, 3H, J=7.2), 1.2 (t, 3H, J=7.5), 1.84 (m, 2H), 2.96 (q, 2H, J=7.5), 5.25 (s, 2H), 5.40 (s, 2H), 6.45 (bs, 3H), 6.83 (s, 1 H), 7.20 (s, 1 H), 9.02 (s, 1H).Low resolution mass spectrometry shows parent ion (M+1) at 393.1 (calcd 393).

Example 22 (S)-(-)-1 1 -Aza-i 0-(3-amino-1 -propynyl)-7-methylcamptothecin trifluoroacetic acid salt In a dry N2-flushed Kontes tube a solution of (S)-(-)-l -aza-10-bromo- 7-methylcamptothecin (50.3 mg, 0.114 mmol) in anhydrous DMF (5.0 mL) was cooled in an ice bath, evacuated and flushed with N2 an additional 2 times, and allowed to warm to ambient temperature. Triethylamine (20 uL, 0.143 mmol) and (PPh3)4Pd (9.8 mg, 8.5 x 10-3 mmol) were added, and the reaction was allowed to stir for 30 min. Tert-butyl-1-propargylaminecarboxylate (84.5 mg, 0.544 mmol) and copper (I) iodide (17.5 mg, 0.092 mmol) were added, and the reaction flask was covered with foil. The reaction mixture was stirred at ambient temperature for 17h, and was concentrated with a rotary evaporator under high vacuum.The residue was purified flask silica chromatography (eluting with 100% ethyl acetate followed by 6:5:1 ethyl acetate/chloroform/methanol) to afford 39.9 mg of N-Boc protected propargyl amine. This material was dissolved in CH2C12 (5.0 mL) and treated with trifluoroacetic add (0.75 mL). The mixture was stirred at ambient temperature for 2h, and the volatiles were removed with a rotary evaporator.The residue was purified by reverse phase HPLC (Dynamax 60A column, eluting with 12820:52 waterlacetonitrile/THF!TFA) to afford, after lyophylization, 38.3 mg (53 /O yield) of the product as a yellow lyophylate, mp 1320C (d). 1H NMR (300 MHz, DMSO-d6): 60,87(t, 3H, 5=7.3), 1.86 (m, 2H), 2.79 (s, 3H), 4.14 (s, 2H), 5.37 (s, 2H), 6.60 (bs, 1H), 7.37 (s, 1H), 8.29 (s, 1H), 8.40 (bs, 2H), 9.49 (s, 1H). Anal. Calcd for C23H20N404.2TFA.1 .5H20: C, 48.29; H, 3.75, N, 8.34. Found: C, 48.36, H, 37.5; N, 8.42. Low resolution mass spectrometry shows parent ion (M+1) at 417.1 (calcd 417).

Example 23 (S)-(-)-1 11 -Aza-1 0-(3-dimethylamino-1 -prnpynvl)J-ethylcamptothecin The procedure of Example 22 was employed substituting (S)-(-)-1 1 -aza-1 0- bromo-7-ethylcamptothecin (15 mg, 0.032 mmol) for the 7-methyl derivative, and using 17.7 uL (0.164 mmol) of 1-dimethylamino-2-prnpyne, 4.0 mg (PPh3)4Pd, 6.7 gL (0.048 mmol) triethylamine, and 5 mg (0.046 mmol) of Cu(l)l in 2.0 mL of DMF.Purification of the crude product by radial chromatography (100% ethyl acetate eluant) afforded 12.0 mg (82% yield) of the product, mp 130"C (d). 1H NMR (300 MHz, DMSO-d6): 61.03 (t, 3H, J=7.2), 1.42 (t, 3H, J=7.5), 1.89 (m, 2H), 2.50 (bs, 6H), 3.16 (q, 2H, J=7.2), 7.64 (s, lH), 8.02 (s, 1H), 9.50 (s, 1H).

Anal. Calcd for C26H26N404.1.5TFA.1.5H2O: C, 53.04; H, 4.68, N, 8.53.

Found: C, 52.97, H, 4.47; N, 8.14. Low resolution mass spectrometry shows parent ion (M+1) at 458.9 (calcd 459).

Example 24 (S)-(-)- 11-Aza-10-(3-(4-methylpiperazino)-1-propynyl)-7-methylcamptothecin The procedure of Example 22 was used with (S)-(-)-1 1 -a::a-1 0-bromo-7- methylcamptothecin (20 mg, 0.0452 mmol), 1-(4-methylpiperazino)-2-propyne (30 mg, 0.217 mmol), Cu(l)l (7 mug, 0.037 mmol), triethylamine (10 uL, 0.072 mmol), and (PPh3)4Pd (10 mg). The workup ånd purification by radial chromatography (100% ethyl acetate eluant) afforded 17.8 mg (78% yield) of the product as a yellow solid, mp 99 C (d). 1H NMR (300 MHz, CDCI3):: 61.03 (t, 3H, J=7.5), 1.89 (m, 2H), 2.34 (s, 3H), 2.54 (bs, 4H), 2.76 (s, 3H), 2.79 (bs, 4H), 3.66 (s, 2H), 3.90 (bs, 1H), 5.27 (s, 2H), 5.30 (d, 1 H, J=16.5), 5.74 (d, 1 H, J=16.5), 7.65 (s, 1 H), 8.01 (s, 1 H), 9.49 (s, 1H). Anal. Calcd for C28H29N504.1.70TFA.2H2O: C, 51.70; H, 4.80, N, 9.60. Found: C, 51.94, H, 4.74; N, 9.66. Low resolution mass spectrometry shows parent ion (M+1) at 500.1 (calcd 500).

Example 25 (S)-(-)-1 1 -Aza-1 0-(3-(N-morpholino)-1 -propynyl)-7-methylcamptothecin The procedure of Example 22 was used with 20 mg (0.045 mmol) of (S)-(-)-1 1- aza-1 0-bromo-7-methylcamptothecin, 1 -(N-morpholino)-2-propyne (30 mg, 0.226 mmol), Cul (7 mg, 0.036 mnmol), triethylamine (10 uL, 0.072 mmol), and (PPh3)4Pd (8 mg).Purification by radial chromatography as above afforded 18.1 mg of the title compound, mp 178-180"C. 1H NMR (300 MHz, CDC13): 6 1.03 (t, 3H, J=7.2), 1.88 (m, 2H), 2.72 (m, 4H), 2.77 (s, 3H), 3.63 (s, 2H), 3.78 (m, 4H), 3.93 (bs, 1 H), 5.27 (s, 2H), 5.29 (d, 1H, J=16.8), 5.73 (d, 1H, J=16.8), 7.26 (s, 1 H), 7.26 (s, 1 H), 7.65 (s, 1 H), 7.99 (s, 1 H), 9.49 (s, 1 H). Anal. Calcd for C27H16N4Os.1.20TFA.2H20: C, 53.55; H, 4.77, N, 8.50. Found: C, 53.89, H, 4.73; N, 8.48. Low resolution mass spectrometry shows parent ion (M+1) at 487.1 (calcd 487).

Example 26 (S)-(-)-1 1 -Aza-1 0-(3-dimethylamino-1 -propynyl)-7-methylcamptothecin The procedure of Example 22 was used with 20.0 mg (45.2 x 10-3 mmol) of (S) (-)-11 -aza-10-bromo-7-methylcamptothecin, 6.6 gL (47 x 1 0-3 mmol) of triethylamine, 5.4 mg (4.7 x 10-3 mmol) of (PPh3)4Pd, 6.5 mg (34.1 x 10-3 mmol) of copper (I) iodide, and 1 -dimethylamino-2-propyne (24.3 uL, 226 x 10-3 mmol) was employed as the alkyne.The volume of DMF used was 2.5 mL The crude reaction was subjected to silica gel chromatography as above to afford 21.1 mg (100% yield) of the product as a yellow sold, mp > 300"C; 1H NMR (300 MHz, CDC13): a 1.05 (t, 3H, J=7.3), 1.90 (m, 2H), 2.45 (s, 6H), 2.78 (s, 3H), 3.60 (s, 2H), 5.29 (s, 2H), 5.32 (d, 1H, J=16), 5.76 (d, 1H, J=16), 7.67 (s, 1 H), 8.04 (s, 1 H), 9.54 (s, 1 H). A sample of the trifluoroacetic acid salt (7.6 mg) was prepared from the free base (8.2 mg) by reverse phase chromatography as described in Example 22: 1 H NMR (300 MHz, DMSO-d6): 60.87(t, 3H, J=7.3), 1.87 (m, 2H), 2.80 (s, 3H), 2.95 (s, 6H), 4.46 (s, 2H), 5.37 (s, 2H), 5.45 (s, 2H), 6.60 (bs, 1H), 7.38 (s, 1H), 8.44 (s, 1H), 9.49 (bs, 1H). Low resolution mass spectrometry shows parent ion at 445.2 (calcd 445.2).

Example 27 (S)-(-)-1 1 -Aza-1 0-(3-hydroxyl- 1 -propynyl)-7-ethylcamptothecin The palladium substitution conditions of Example 22 were employed using 20 mg (0.44 mmol) of (S)-(-)-1 1-aza-10-bromo-7-ethylcamptothecin, 5 mg (PPh3)4Pd, 9.2 lli (0.066 mmol) of triethylamine, 6.7 mug (0.035 mmol) of Cu(l)l, and substituting propargyl alcohol (11.5 uL, 0.198 mmol) for the propargyl amine.The workup and radial chromatograph afforded 18 mg (95% yield) of the product, mp 163"C. 1H NMR (300 MHz, DMSO-d6): 60,87(t, 3H, J=7.5), 1.26 (t, 3H, J=7.4), 1.86 (m, 3H), 3.22 (q, 2H, J=7.4), 4.41 (d, 2H, J=6.0), 5.38 (s, 2H), 5.44 (s, 2H), 5.49 (t, 1 H, J=6.0), 6.56 (s, 1 H), 7.36 (s, 1H), 8.29 (s, 1 H), 9.46 (s, 1H). Low resolution mass spectrometry shows parent ion at 432.0 (calcd 432).

Example 28 (S)-(-)-i 1 -aza-i 0-(3-dimethylaminopropyl)-7-ethylcamptothecin trifluoroacetic acid salt A sample of (S)-(-)-11 -Aza-10-(3-dimethylamino-1 -propynyl)-7methylcamptothecin (12 mg, 0.026 mmol) with 10% palladium on carbon (7 mg) in glacial acetic acid (1.5 mL) was stirred under 1 atm H2 for 4h.The reaction was filtered and subjected to reverse phase HPLC using the conditions described above to afford 6 mg (40% yield) of the title compound as a yellow powder, mp 115-117 C (d). 1H NMR (300 MHz, DMSO-d6): 6 0.85 (t, 3H, J=7.5), 1.40 (t, 3H, J=7.5), 0.85 (m, 2H), 2.18 (quintet, 2H, J=7.5), 5.38 (s, 2H), 5.43 (s, 2H), 6.65 (bs, 1 H), 7.37 (s, 1 H), 8.03 (s, 1 H), 9.38 (bs, 1 H), 9.49 (s, 1 H).

Anal. Calcd for C26H30N404.1.5TFA.1H2O: G, 53.45, H, 5.18; N, 8.60.

Found: C, 53.28; H, 5.01; N, 8.74. Low resolution mass spectrometry shows parent ion at 463.1 (calcd 463).

Example 29 (S)-(-)-i 1 -aza-7-methyl-i 0-(5-tetrazolo)camptothecin A small flask was charged with (S)-(-)-1 1 -aza-1 0-cyano-7-methylcamptothecin (10.2 mg, 26.2 x 10-3 mmol) and tributyltin azide (300 iiL) and the mixture was heated at 90-95 C for 19h. The excess tributyltin azide was removed by Kugulrohr (100"C) to afford the crude tetrazolo tributyltin derivative as a orangebrown residue. This material was stirred vigorously in a two phase mixture of 1 M HCI (2.0 mL) and 5:1 chloroform/isopropanol (1 mL) for 2h. The aqueous layer was decanted, and the organic layer was washed with H2O (2 x 1 mL).

The combined aqueous layers were extracted with 5:1 CHCI3/isopropanol (2 mL), and the combined organic layers were dried over Na2S04. The solution was concentrated with a rotary evaporator and the residue was purified by silica gel chromatography (5:1 CHCI3/methanol to 1:1 CHCI3/methanol eluant) to afford 7.3 mg of the product as a pale yellow solid, mp 280"C (d). 1H NMR (300 MHz, DMSO-d6): 60.88(t, 3H, J=7.1), 1.89 (m, 2H), 2.82 (s, 3H), 5.36 (s, 2H), 5.44 (s, 2H), 6.58 (s, 1H), 7.36 (s, 1H), 8.65 (bs, 1H), 9.52 (bs, 1 H). Low resolution mass spectrometry (M+1) shows parent ion at 432.1 (calcd 432).

Example 30 (S)-(-)-i 1 -Aza- 1 0-acetami nomethyl-7-methylcamptothecin A slurry of (S)-(-)-1 1 -aza-1 0-aminomethyl-7-methylcamptothecin trifluoroacetic acid salt (15.1 mg, 29.8 x 10-3 mmol) in anhydrous CH2C12 (2.5 mL) was treated with triethylamine (27 uL, .194 mmol) and acetic anhydride (15 uL, 0.159 mmol). The reaction mixture was allowed to stir at ambient temperature for 2h, and partitioned between 5:1 CHCI31isopropanol (10 mL), and water (10 mL).

The organic layer was separated, and the aqueous layer was extracted with 5:1 CHCl3/isopropanol (5 mL). The combined organic layers were dried over Na2S04, filtered and concentrated to afford 9.9 mg of the product as a pale yellow solid, mp 278"C (d). 1H NMR (300 MHz, CDC13): 61.04(t, 3H, J=7.3), 1.85 (m, 2H), 2.10 (s, 3H), 2.78 (s, 3H), 4.76 (d, 2H, J=5.4), 5.29 (s, 2H), 5.31 (d, 1 H, J=1 6.4), 5.75 (d, 1 H, J=16.4), 6.70 (bs, 1 H), 7.68 (s, 1 H), 7.87 (s, 1 H), 9.55 (s, 1H). Low resolution mass spectrometry (M+1) shows parent ion at 435.1 (calcd 435).

Example 31 (S)-(-)- 11 -Aza-1 0-acetaminomethyl-7-methylcamptotheci n-1 1-oxide A mixture of (S)-(-)-1 1 -Aza-1 0-acetaminomethyl-7-methylcamptothecin (9.0 mg, 22.8 x 10-3 mmol) obtained as in Example 30 and mchloroperbenzoic acid (15 mg 50-60%, ca 0.045 mmol) was dissolved in dry CH2C12 (4.5 mL). The solution was stirred at ambient temperature for 18h.The volatiles were removed with a rotary evaporator and the residue was purified by silica gel chromatography (6:5:1 ethyl acetate/chloroform/methanol elution) to afford the product (5.9 mg, 57% yield) as a yellow solid. 1H NMR (300 MHz, CDC13): 6 1.04 (t, 3H, J=7.3), 1.88 (m, 1 H), 2.00 (s, 3H), 2.79 (s, 3H), 4.80 (d, 2H, J=4.9), 5.26 (s, 2H), 5.31 (d, 1H, J=16.6), 5.75 (d, 1H, J=16.6), 7.64 (s, 1H), 8.13 (s, 1 H), 9.12 (s, 1 H). Low resolution mass spectrometry (M+1) shows parent ion at 450.9 (calcd 451).

Example 32 (S)-(-)-1 1 -Aza-1 0-t-buty(oxycarbonylaminomethyl-7-methylcamptothecin-i I oxide A slurry of (S)-(-)-1 I -aza-1 0-aminomethyl-7-methylcamptothecin triluoroacetic acid salt (186.5 mg, 0.42 mmol) obtained as in Example 12 in anhydrous CH2C12 (25 mL) was treated with ditert-butylcarbonate (180.5 mg, 0.827 mmol) and triethylamine (0.5 mL, 3.59 mmol). The mixture was allowed to stir at ambient temperature for 1.5h. Additional ditert-butylcarbonate (56 mg, 0.26 mmol) was added, and the mixture was stirred for a further 1.25h.The mixture was partitioned between H2O (50 mL) and CH2C12 (50 mL). The organic layer was separated and dried over Na2504, filtered and concentrated to afford a greenish residue. Purification by silica gel chromatography (6:5:1 ethyl acetate/CHC13/methanol with 1% triethylamine as eluant) afforded 128.7 mg of the 11 -aza-1 I -N4-Boc-aminomethyl derivative. This material was treated with m-chloroperbenzoic acid (135.0 mg, 50-60%, ca. 0.4 mmol) and NaHC03 in CH2C12 (20 mL). The slurry was stirred at ambient temperature for 7h, and partitioned between CH2C12 (50 mL) and aqueous Na2S03 (20 mL).The organic layer was separated, and washed with H20 (10 mL). The combined aqueous layers were extracted with CH2C12 (20 mL), and the combined organic layers were dried over Na2SO4, filtered and concentrated to afford the crude product (164.7 mg) as a yellow solid. This material was purified by flask chromatography (eluting with 100% ethyl acetate followed by 6:5:1 ethyl acetate/CH2C12/methar)ol containing 1% triethylamine) to afford 84.5 mg (40% overall yield) of the product as a bright yellow solid, mp 250"C (d). 1H NMR (300 MHz, CDCI3): a 1.04 (t, 3H, J=7.3), 1.41 (s, 9H), 2.78 (s, 3H), 4.66 (s, 2H), 5.25 (s, 2H), 5.30 (d, 1H, J=16.6), 5.74 (d, 1H, J=16.6), 7.63 (s, 1H), 8.01 (s, 1H), 9.10 (s, 1H). Anal.Calcd for C26H2gN407.H2O: C, 59.31; H, 5.74; N, 10.64. Found: C, 59.22; H, 5.74; N, 10.65. Low resolution mass spectrometry (M+1) shows parent ion at 509.0 (calcd 509).

Example 33 IS)-(-)-I -Aza-i 0-aminomethyl-7-methylcamptothecin-1 dioxide trifluoroacetic acid salt A solution of (S)-(-)-11 -aza-10-t-butyloxyearbonyl-aminomethyl-7- methylcamptothecin-11-oxide (79.3 mg, 0.156 mmol) obtained as in Example 32 in CH2C12 (28 mL) was treated with trifluoroacetic acid (1.35 mL). The solution was stirred at ambient temperature for 4.5h, and concentrated with a rotary evaporator to leave 92.5 mg of the crude product.Purification by reverse phase HPLC using the conditions described above afforded 82.8 mg of the product as a bright yellow lyophylized powder, mp 17000 (d). 1H NMR (300 MHz, DMSOd6): a 0.88 (t, 3H, J=7.1), 1.86 (m, 2H), 2.76 (s, 3H), 4.39 (d, 2H, J=4.9), 5.32 (s, 2H), 5.44 (-s, 2H), 8.32 (s, 1H), 8.56 (s, 1 H), 9.27 (s, 1 H). Anal. Calcd for C23H20N406.2TFA.2.5H20: C, 44.13; H, 3.85; N, 8.23. Found: C, 44.12; H, i.o8;-N, 8.14. Low resolution mass spectrometry (M+1) shows parent ion at409.0 (calcd 409)..

Example 34 (S)-(-)-1 1 -Aza-7-methyl-10-vinylcamptothecin A dry, N2-flushed flask was charged with (PPh3)4Pd (40 mg, 0.035 mmol), vinyltributyltin (132 uL, 0.452 mmol), and anhydrous 1,2-dichloroethane (10 mL).

The mixture was heated in an oil bath at 85 C for 30 min, and (S)-(-)-1 1 -aza-1 0- bromo-7-methylcamptothecin (99.6 mg, 0.225 mmol) was added. The mixture was heated at a gentle reflux (oil bath temperature of 85"C) for 18h. The mixture was allowed to cool to ambient temperature and concentrated with a rotary evaporator to afford a tan solid which was triturated with ethyl acetate to afford 63.3 mg (72% yield) of the product, mp 275 C. 1H NMR (300 MHz, DMSO-d6): 60.86(t, 3H, J=7.2), 1.29 (t, 3H, J=7.2), 1.85 (m, 2H), 3.20 (q, 2H, J=7.2), 5.36 (s, 2H), 5.57 (d, 1H, J=11.1), 6.47 (d, 1H, J=17.1), 6.54 (s, 1H), 7.09 (dd, 1H, J=17.1, 11.1), 7.35 (s, 1 H), 8.11 (s, lH), 9.47 (s, 1H). Low resolution mass spectrometry (M+1) shows parent ion at 404.0 (calcd 404).

Example 35 1S)-(-)-l 1 -Aza-1 0-hydroxymethyl-7-methylcamptothecin A mixture of (S)-(-)-l l-aza-7-methyl-l O-vinylcamptothecin (45 mg, 0.112 mmol) obtained as in Example 34 in 5:1 dioxane/water (10 mL) was treated with catalytic OsO4 (1 crystal), and powdered NalO4 (85 mg, 0.40 mmol) was added slowly. The mixture was stirred at ambient temperature for 2h, and filtered through a pad of Celite. The filtrate was extracted with 5:1 CHC13/i-PrOH (40 mL). The organic extract was separated, dried over Na2SO4, filtered and concentrated to afford the crude aldehyde, which was taken immediately into the next step to avoid decomposition. This material was taken up in anhydrous CH2CI2 (45 mL), and cooled to -780C under N2.A solution of lithium tritertbutoxyaluminum hydride (0.23 mL of.a 1.0 M solution in THF, 0.23 mmol) was added dropwise, and the mixture was stirred at -78 C for 10 min. The mixture was quenched by the addition of acetic acid (1.0 mL), and concentrated to afford the crude produce. Purification by radial chromatography afforded 10 mg of the product (23% yield) of the product as an off white solid. 1H NMR (300 MHz, DMSOd6): 60.87(t, 3H, J=7.2), 1.86 (m, 2H), 2.77 (s, 3H), 4.81 (d, 2H, J=5.4), 5.35 (s, 2H), 5.43 (s, 2H), 5.69 (t, 1 H, J=5.4), 5.74 (s, 1 H), 6.54 (s, 1 H), 7.35 (s, 1 H), 8.08 (s, 1H), 9.44 (s, 1 H). Low resolution mass spectrometry (M+1) shows parent ion at 394.0 (calcd 394).

Example 36 (S)-(-)-1 1 -Aza-I 0-carboxaldehyde-7-methvlcamptotheci n-1 0-hydrazone from Girardts Reagent T A sample of crude (S)-11-aza-10-carboxaldehyde-7-methylcamptothecin (5 mg) prepared from the Nay0\4 cleavage of the 10-vinyl derivative as described in the foregoing procedure was taken up in ethanol (2 mL) and Girard's Reagent T ((carboxymethyl)trimethylammonium chloride hydrazide) (6.0 mg, 0.036 mmol) was added. The mixture was heated at reflux for 30 min.The reaction mixture was allowed to cool to ambient temperature and concentrated to afford a brown residue that was purified by reverse phase HPLC (C-8 Dynamax 60A column, eluting with 80:20 A:B, A=2% TFA in water, B=4:1 acetonitrile/THF) to afford, after collecting the major UV-active fraction, concentrating and lyophylizing, 3.0 mg of the title compound as a yellow brown powder. 1H NMR (300 MHz, DMSOd6): 80.87 (t, 3H,J=7), 1.88 (m,2H), 2.85 (s, 3H), 3.25 (q, 2H, J=7), 4.92 (s, 2H), 5.39 (s, 2H), 5.43 (s, 2H), 5.75 (s, 9H), 6.60 (s, 1 H), 7.40 (s, 1 H), 8.38 (s, 1 H), 8.50 (s, 1 H), 9.59 (s, 1 H). Low resolution mass spectrometry shows parent ion at 505.2 (calcd 505).

Example 37 (S)-(-)-i I -Aza-i 0-carboxamido-7-methylcamptothecin A solution of 1:1 toluene/saturated absolute ethanolic HCI (15 mL) was heated at reflux for 10 min, and (S)-(-)-11 -aza-10-cyano-7-methylcamptothecin was added. The mixture was heated at reflux for 50 min, during which time a yellow precipitate formed.The mixture was concentrated to approximatley 1/3.volume with a rotary evaporator, and the solid was collected by suction filtratiori änd dried en vacuo to afford 10.7 mg (31% yield) of the title compound as a tan solid. 1H NMR (300 MHz, DMSO-d6): 80.93 (t, 3H, J=7), 1.85 (m, 2H), 2.87 (s, 3H), 5.39 (s, 2H), 5.43 (s; 2H), 7.40 (s, 1 H), 7.88 (s, 1 H), 8.39 (s, 1 H), 8.75 (s, 1 H), 9.53 (s,1 H). Low resolution mass spectrometry shows parent ion (M+1) at 407.0 (calcd 407).

Example 38 (S)- 11 -Aza-10-(O-(N-tertbutyloxycarbonyl)glycinoyl)-carboxamidoximo-7- ethylcamptothecin To a 50C mixture of N-tert-butyloxycarbonyl glycine (174.7 mg, 1.0 mmol) in CH2Cl2 (2.0 mL) was added isobutylchloroformate (125 I1L, 0.96 mmol). After stirring the mixture for 25 min at -400C to -50 C for 25 min, 200 CLL was transferred via gas tight syringe to a -30 C partially dissolved slurry of (S)-11-aza-10arboxamidoxime4-ethylcamptothedn(15.8 mg, mg, 0.0363 mmol) in 3:1 dioxane/CH2CI2 (2.0 ml). The reaction mixture was allowed to warm to ambient temperature and stirred for 10 min, during which time all solids dissolved.The solution was partitioned between water (10 mL) and 10:1 CH2C12/methanol (15 mL). The organic layer was separated, washed with water, dried over Na2SO4, filtered and concentrated to afford 25.1 mg (quantitative yield) of the title compound contaminated with a small amount of N-tertbutyloxy glycine. 1H NMR (300 MHz, DMSO-d6) 60.87 (t, 3H, J=7), 1.33 (t, 3H, J=7), 1.40 (s, 2H), 6.57 (s, 1 H), 7.20 (bs, 2H), 7.30 (t, 1 H, j=6), 7.40 (s, 1 H), 8.58 (s, 1 H), 9.60 (s, 1 H). Low resolution mass spectrometry shows parent ion (M+1) at 593.2 (calcd 593).

Example 39 (S)-(-)-11-Aza-7-methylcamptothecin (A) (R ,S)-3-Nitro-4-(1 -hydroxyethyl)pyridine: A dry nitrogen-flushed round-bottomed flask was charged with 3-nitro-4-pyridine carboxaldehyde (J. Am. Chem. Soc. 1955 77, 2438) (520 mg, 3.41 mmol) and an hydros THF (12.0 mL). The solution was cooled to -780C, and methyl lithium (2.44 mL of a 1.4 M solution in diethyl ether, 3.42 mmol) was added dropwise over 10 min. The reaction was allowed to stir at -78 C for 25 min, and quenched by addition of saturated aqueous NaHC03 (10 mL). The mixture was extracted with ethyl acetate (3 times 30 mL), and the combined organic extracts were dried over Na2504, filtered and concentrated to afford an orange semisolid.Purification by radial silica gel chromatography (2:1 hexanes/ethyl acetate followed by 1:1 hexanelethyl acetate) provided 274 mg (50% yield) of the product as a yellow semi-solid. 1H NMR (300 MHz, acetone-d6): delta 1.55 (d, 3H, J=6.5), 3.04 (bs, 1H), 5.54 (q, 1H, J=6.5), 7.84 (d, 1H, J=5.1), 8.78 (d, 1H, J=5.1), 9.10 (s, 1H). Anal. Calcd for C7HgN203: C, 50.00; H, 4.80; N, 16.66. Found: C, 50.26; H, 4.82; N, 16.73.

(B) 3-Nitro-4-(1-oxoethyl)pyridine A round-bottomed flask was charged with (R,S)-3-nitro-4 (1 -hydroxyethyl)pyridine (268 mg, 1.59 mmol), Dess-Martin periodinane (J. Org.

Chem. 1983, 48, 4155) (1.35 g, 3.19 mmol) and dry CH2CI2 (25 mL), and the yellow slurry was stirred at ambient temperature for 14 h. The mixture was passed through a pad of celite, washing with ca. 50 mL ether, then through a pad of silica gel. The resulting solution was washed with saturated aqueous NaHCO3 followed by brine, and dried over Na2SO4. Filtering and concentrating the solution afforded the product (234 mg, 88% crude yield) as a yellow semi-solid. 1H NMR (300 MHz, Acetone-d6): delta 2.60 (s, 3H), 7.37 (d, 1 H, J=5), 8.96 (d, 1 H, J=5), 9.38 (s, 1 H).

(C) 3-Amino-4-(1-oxoethyl)pyridine In a small round-bottomed flask were combined 3-nitro-4-(1-oxoethyl)pyridine (550 mg, 3.31 mmol) and sodium dithionite (3.45 g, 19.87 mmol). The mixture was taken up in 95% ethanol (35 mL), and the mixture was heated at reflux for 15 h. The mixture was allowed to cool to room temperature, and concentrated with a rotary evaporator. The residue was partitioned between ethyl acetate (30 mL) and water (30 mL). The organic layer was separated, and the aqueous layer was re-extracted with ethyl acetate (2 times 30 mL).The combined organic layers were dried over Na2SO4, filtered and concentrated with a rotary evaporator and the residual solvent removed with high vacuum to afford 320 mg (70% yield) of the product as a yellow semi-solid. 1H NMR (300 MHz, Acetoned6): delta 2.59 (s, 3H), 7.43 (d, 1H, J=5.1), 7.93 (d, IH, J=5.1), 8.21 (s, 1H).

Anal.: Calcd for C7HgN20: C, 61.75; H, 5.92; N, 20.58. Found: C, 61.65, H, 5.97; N, 20.39.

(D) (S)-(-)-1 1 -Aza-7-methylcamptothedn A small round-bottomed flask was charged with (S)-(-)-tricyclic ketone (257 mg, 0.977 mmol), and 3-amino-4-(1 -oxoethyl)pyridine (115 mg, 0.851 mmol) and anhydrous toluene (15 mL). The mixture was heated at reflux for 20 min, and allowed to cool to room temperature. Catalytic p-toluenesulfonic acid (5 mg) was added, and the mixture was heated at reflux for 3 days. The brown mixture containing some solid precipitate was allowed to cool to room temperature, and concentrated with a rotary evaporator.The brown residue was dissolved in a minimum amount of' 5:1 OHCLW methanol, and subjected to radial chromatography (eluting with 100% ethyl acetate followed by 12:5:1 ethyl acetate/CHCI3/ methanol followed by 6:5:1 ethyl acetate/CHCI3/methanol) to afford 62 mg (21% yield) of the product as a yellow solid, mp 160 OC (decomp).

Nominal Mass Spectrum(M+1): 364 (calcd. 364.3.

Example 40 (S)-(-)-i I -Aza-7-methylcamptothecin-i 1-N-oxide: To a small round-bottomed flask was added (S)-(-)-1 1 -aza-7- methylcamptothecin (7.4 mg, 0.0212 mmol) prepared as in Example 39, mchloroperbenzoic acid (10.9 mg, 5040%, 0.32-0.35 mmol) and dry CH2C12 (5.0 mL). The mixture was stirred at room temperature for 14 h, until monitoring by thin layer chromatography showed the disappearance of starting material. The reaction mixture was partitioned between 5:1 CHC13/isopropanol (10 mL) and water (10 ml) and the aqueous layer was re-extracted with 5:1 CHC13 sopropanol (2 times 10 mL).The combined organic layers were dried over Na2SO4, filtered and concentrated to afford a yellow solid residue which was purified by silica gel chromatography (eluting with 100% ethyl acetate followed by 6:5:1 ethyl acetate/CHC13/methanol) to afford 7.3 mg (97% yield) of the product as a bright yellow solid, mp 217-220 C. Nominal Mass Spectrum (M+1): 380 (calcd. 380.3).

Example 41 (S)-(-)-11-Aza-7-methylcamptothecin-11-N-methyllodide A sample of (S)-(-)-1 I -aza-7-methylcamptothecin (12 mg, 0.033 mmol) prepared as in Example 39, was taken up in 1:1 chloroformlmethanol (5 mL), and iodomethane (1.4 mL) was added. The mixture was stirred af ambient temperature for 14 h, then at 35-40 "C for 3 days. Monitoring the reaction by thin layer chromatography showed the formation of a highly UV active spot at baseline (5:1 chloroform/methanol eluant).The mixture was concentrated with a rotary evaporator to leave a dark residue, which was dissolved in a few mL of 4:1 water/acetonitrile. this slurry was passed through a fine glass frit, and the filtrate was concentrated with a rotary evaporator (high vacuum) to afford the product (5.5 mg, 33% yield) as a brown solid. 1H NMR (300 MHz, DMSC-d6): delta 0.87 (t, 3H, J=7.5), 1.80-1.95 (m, 2H), 2.89 (s, 3H), 4.58 (s, 3H), 5.45 (s, 4H), 7.40 (s, 1H), 8.82 (d, 1 H, J=5.5), 8.95 (d, 1 H, J=5.5), 10.20 (s, 1H).

Nominal Mass Spectrum (M+1): 378 (calcd. 378.3).

Example 42 (S)-(-)-1 1 -Aza-7-ethylcamptothecin (A) (R,S)-4-(1-Hydroxypropyl)-3-nitropyridine A solution of 3-nitro-4-pyridinecarboxaldehyde (1000 mg, 6.58 mmol) in an hydrous toluene (100 mL) was cooled to -78"C and tetramethylethylenediamine (TMEDA) (248 uL, 1.65 mmol) was added, followed by diethylzinc (19.7 mL of a 1.0 M solution in toluene, 19.7 mmol), the. latter being added dropwise slowly. After 5 min, the reaction was allowed to warm to room temperature over 30 min, and poured into saturated aqueous sodium potassium tartrate (100 mL). The mixture was stirred vigorously for 30 min, and extracted with ethyl acetate (2 times 100 mL). The combined organic layers were dried over Na2SO4, filtered and concentrated to afford the crude product as red semi-solid.Purification by radial chromatography (1:1 hexanelethyl acetate) afforded 607 mg (51 % yield) of the product as a yellow semi-solid. 1H NMR (300 MHz, CDCI3): delta 1.01 (t, 3H, J=7.2), 1.66 (m, 1H); 1.77 (m, 1H), 3.73 (bs. 1H), 5.29 (d, 1H, J=7.5), 7.78 (d, 1H, J=5.1), 8.71 (d, 1H, J=5.1), 9.03 (s, 1 H). Low resolution mass spectroscopy shows parent ion (MH+) at 183 mu.

(B) 4-(1 -Oxopropyl)-3-nitropyridine To a solution of (R,S)-4-(1-hydroxypropyl)-3-nitropyridine (34 mg, 0.187 mmol) in dry CH2C12 (4.0 mL) was added Dess-Martin periodinane (160 mL, 0.374 mmol). The slurry was stirred at ambient temperature for 14 h. The solvent was removed with a rotary evaporator, and the residue was purified by a radial chromatography (1:1 hexane/ethyl acetate) to afford 34 mg of a yellow solid which 1H NMR showed to be the desired compound contaminated by a trace of periodinane-related impurities (100% crude yield). The material was used in this run and in subsequent reactions without further purification. 1H NMR (300 MHz, CDCI3): delta 1.25 (t, 3H, J=7), 2.80 (q, 2H, J-7), 7.29 (d, 1 H, J=5), 8.93 (d, IH, J=5), 8.39 (s, lah).

(C) 3-Amino-4-(1 -oxopropyl)pyridine A mixture of 4-(1-oxopropyl)-3-nitropyridine (34 mg, 0.189 mmol) and sodium dithionite (197 mg, 1.13 mmol) in 95% ethanol (3.0 mL) was heated at reflux for 14 h. The mixture was allowed to cool to ambient temperature, and the solvent was removed with a rotary evaporator. Purification by radial chromatography afforded 13 mg (48% yield) of the product as a bright yellow semi-solid. 1H NMR (300 MHz, CDC13): delta 1.21 (t, 3H, J-7.5), 2.00 (q, 2H, J-7.5), 6.20 (bs, 1 H), 7.50 (d, 1 H, J=5.4), 7.94 (d, 1 H, J=5.4), 8.25 (s, 1 H). Low resolution mass spectroscopy shows parent ion (MH+) at 151 mu.

(D) (S)-(-)-1 I -Aza-7-ethylcamptothedn A mixture of 3-amino-4-(1 -oxopropyl)pyridine (13 mg, 0.087 mmol) and (S)-(-)- tricyclic ketone (29.6 mg, 0.113 mmol) in anhydrous toluene (1 mL) was heated at reflux for 10 min. The mixture was allowed to cool to just below reflux, and catalytic p-toluenesulfonic add (3 mg) was added. The mixture was heated at reflux for 48 h, at which time TLC monitoring showed the disappearance of starting pyridine and formation of a new, strongly UV active compound.The reaction was allowed to cool to ambient temperature, and the solvent was removed with a rotary evaporator The residue was purified by radial chromatography to afford 14 mg (43% yield) of the product as a tan solid, mp 150 "C (decomp). 1H NMR (300 MHz, DMSO-d6): delta 0.85 (t, 3H, J=7), 1.27 (t, 3H, J=7), 1.80-1.95 (m, 2H), 3.30 (q, 3H, J=7), 5.38 (s, 2H), 5.42 (s, 2H), 6.57 (s, 1 H), 7.39 (s, 1 H), 8.18 (d, 1 H, J-5), 8.69 (d, I H, J-5), 9.55 (s, 1 H). Nominal Mass Spectrum (M+1): 378 (calcd. 378.2).

Example 43 (S)-(-)-1 1 -aza-7-ethylcamptothecin-i 1 -N-methyliodide A sample of 11-aza-7-ethylcamptothecin (45 mg, .119 mmol) prepared as in Example 7, was dissolved in 1:1 chloroform/ methanol (5.5 mL) and iodomethane (5 mL) was added. The mixture was heated at 35-400C for 5 days.

The reaction mixture was concentrated to dryness and dissolved in 5:1 water/acetonitrile, and filtered through a cotton plug. The filtrate was concentrated to leave the product as a red-orange solid, mp 213-215"C.

Nominal Mass Spectrum (M+1): 392 (calcd. 392.4).

Example 44 (R .S)-i 1 -Azacamptothecin A round-bottomed flask was charged with 3-(3-amino-4-picolylidene)-p-toluidine (263 mg, 1.25 mmol) and (R,S)-tricyclic ketone (327 mg, 1.25 mmol) and anhydrous toluene (15.0 mL). A condenser and Dean-Stark trap with molecular sieves were attached, and the slurry was heated at reflux for 10 min. The homogenous solution was cooled to just below reflux, and catalytic ptoluenesulfonic acid (2.5 mg) was added. The mixture was heated at reflux for 16 h, and allowed to cool to room temperature.The mixture was concentrated with a rotary evaporator, and the dark residue was purified by flash chromatography (eluting sequentially with ethyl acetate followed by 5:1 chloroforrn(methanol) to afford 127.4 mg (29% yield) of the title compound as a tan powdery solid, mp 291-292 C. Nominal Mass Spectrum (M+1): 350 (calcd.

350.3).

Example 45 A small round-bottomed flask was charged with (R,S)-1 acamptothecin (5.0 mg, 0.014 mmol) and anhydrous CH2CI2 (0.75 mL). The yellow solution was cooled to 0 C in an ice bath, and m-chloroperbenzoic acid (6.2 mg, 50-60%) was added. The solution was allowed to warm to room temperature and stirred for 17 h. The reaction mixture was partitioned between 5:1 chloroform/isopropanol (20 mL) and saturated aqueous sodium sulfite (10 mL) which was neutralized by addition of a few drops acetic acid. The organic layer was separated, and the aqueous layer was re-extracted with 5:1 chloroform/isopropanol 42 times 10 mL).The combined organic layers were dried over anhydrous Na2S04, filtered and concentrated to leave a yellow residue which was purified by silica gel chromatography (6:5:1 ethyl acetate/chloroform- methanol followed by 5:1 chloroformlmethanol elution) to afford 4.2 mg (82%) of the title compound as a bright yellow powder, mp 255 C (dec). Nominal Mass Spectrum (M+1): 366 (calcd. 366).

Example 46 (S)-(-)- ii -Aza-1 0-(3-amino-1 -propynyl)-7-ethylcam ptothecin The procedure followed was the same as Example 22 except that (S)-(-)-i 1 -aza- 1 0-bromo-7-ethylcamptothecin (100mg, 0.21 9mmol) was substituted for the 7methyl derivative, and 163mg (1.05mmol) of tert-butyl-1 - propargylami necarboxylate, 27mg (0.026mmol) of (P Ph3)4Pd, 33.3mg (0.175mmol) of copper (I) iodide, and 46111 (.33mmol) of triethylamine in 7.5ml anhydrous DMF was used.The reaction afforded, after silica gel chromatography, 56mg (48% yield) of t-Boc protected amine, which was dissolved in 2.5ml anhydrous CH2Cl2 with 0.35ml trifluoroacetic acid and stirred for 5h. The reaction mixture was concentrated and the crude product was purified by reverse phase chromatography as described in Example 22 to afford 52mg of the title compound as a yellow solid, mp 175-177 C. Low resolution mass spectrometry shows parent ion (M+1) at 431.2 (calcd 431).

Example 47 (S)-(-)-11-Aza-7-ethyl-10-vinylcamptothecin The procedure followed was the same as Example 34 with the following modifications: (S)-(-)-1 1-aza-10-bromo-7-ethylcamptothecin (100mg, 0.21 9mmol) was substituted for the corresponding 7-methyl derivative, 25mg (0.022mmol) of (PPh3)4Pd was used as catalyst, and 128111 (0.438mmol) of vinyltributyltin was employed as reagent Workup afforded 73mg (82% yield) of the product as a yellow solid, mp 15000. 1H NMR (300 MHz, DMSOd6): : a 0.86 (t, 3H, J=7.2), 1.29 (t, 3H, J=7.2), 1.85 (m, 2H), 3.20 (q, 2H, J=7.2), 5.36 (s, 2H), 5.57 (d, 1H, J=11.1), 6 47 (d, 1H, J=17.1), 6.54 (s, 1H), 7.09 (dd, 1H, J=17.1, 11.1), 7.35 (s, 1 H), 8.11 (s, 1 H), 9.47 (s, 1 H). Low resolution mass spectrometry shows parent ion (M+1) at 404.0 (calcd 404).

Example 48 (S)-(-)-11-Aza-10-carboxy-7-methylcamptothean A sample of (S)-(-)-11 -aza-1 0-cyano-7-methylcamptothecin (Example 7) (5.6mg, 0.01 4mmol) was dissolved in 6N aqueous hydrochloric acid (2ml) and the solution was heated at reflux for 18h. Monitoring by reverse phase HPLC (Rainin C-8 Dynamax 60A analytical column, eluting with 98:20:5:2 water/acetonitrile/THF/trifluoroacetic acid, flow rate 1.Sml/min) showed the presence of the product as a strong peak (monitoring at 254nm) with a retention time of 3.3min. The reaction mixture was stripped with a rotary evaporator to afford the crude product.Purification by reverse phase HPLC (Rainin Dynamax 60A semi-preparative column, eluting with 98:20:5:2 waterlacetonitrile/THF/TFA) afforded, after lyophylization of the most intense UV active fraction, 1 mg of the product as a tan powder. 1H NMR (300 MHz, DMSOd6): 60.85 (t, 3H, J=7), 1.86 (m, 2H), 2.82 (s, 3H), 5.37 (s, 2H), 5.42 (s, 2H), 7.40 (s, 1H), 8.75 (s, 1H), 9.55 (s, 1H). Low resolution mass spectrometry shows parent ion (M+1) at 408.2 (calcd 408).

Example 49 )-(-)-1 1 -Aza-7-phenylcamptothecin (A) (R,S)-4-(1 -Hydroxy-1 -phenylmethyl)-3-nitropyridine A dry N2-flushed flask was charged with 3-mtro4-pyridinecarboxaldehyde (100mg, 0.658mmol) and the solution was cooled to -7800. A solution of phenylmagnesium bromide in THF (0.24ml of a 1 .0M solution, 0.24mmol) was added dropwise, and the mixture was allowed to stir at -78"C for 10 min. The reaction was quenched by addition of saturated aqueous potassium sodium tartrate (1 oil), and the mixture was extracted with ethyl acetate (3 x 1 Oml). The combined ethyl acetate layers were dried and concentrated to afford the crude product.Purification by radial chromatography afforded 120mg of an inseparable 1.5:1 mixture of product alcohol: starting aldehyde. 1H NMR (300, CDC13): 66.50 (s, lH), 7.20-7.40 (m, 5H), 7.90 (d, 1H, J=6), 8.75 (d, 1H, J=6), 8.75 (s, 1 H). tow resolution mass spectrometry shows parent ion (M+1) at 231 (calcd 231).

(b) 4-(1 - P henyl- 1 -oxomethyl)-3-nitropyridine To a solution of (R,S)-4-(I -hydroxy-1 -phenylmethyl)-3-nitropyridine (120mg of a 1.5:1 mixture contaminated with 3-nitro-4-pyridinecarboxaldehyde) in CH2CI2 was added Dess Martin periodinane (298mg, 0.696mmol). The mixture was stirred at ambient temperature for 5h. The solvent was removed and the residue was taken up in 1:1 hexane/ethyl acetate and filtered through a pad of Celite.

The filtrate was concentrated and purified by radial chromatography (1:1 hexanes/ethyl acetate) to afford 75mg (62%) of the product. 1H NMR (300 MHz, CDCl3): 67.44 (d, 1 H, J=6), 7.49 (t, 2H, J=8), 7.64 (t, 1 H, J=8), 7.74 (d, 2H, J=8), 9.00 (d, 1 H, J=1 H), 9.49 (s, 1 H). Low resolution mass spectrometry shows parent ion (M+1) at 229 (calcd 229).

(C) 4-(1 -Phenyl-1 -oxomethyl)-3-aminopyridine A solution of 4-(1 -phenyl-1 -oxomethyl)-3-nitropyridine (7Omg, 0.307mmol) in 95% ethanol (8ml) was treated with Na2S204 (320mg, 1.84mmol) and the mixture was heated at reflux for 12h. The solvent was removed with a rotary evaporator and partitioned between ethyl acetate and water. The ethyl acetate layer was separated, dried over Na2SO4, filtered and concentrated to afford 38mg (63%) of the product. 1H NMR (300, CDC13): 65.8 (bs, 2H), 7.23 (d, 1 H, J=6), 7.50 (t, 2H, J=8), 7.59 (t, 1H, J=8), 7.68 (d, 2H, J=8), 7.93 (d, 1H, J=6), 8.30 (s, 1 H). Low resolution mass spectrometry shows parent ion (M+1) at 199 (calcd 199).

(D) (S)-(-)-11-Aza-7-phenylcamptothecin A mixture of 4-(l-phenyl-l -oxomethyl)-3-aminopyridine (38mg, 0.19mmol) and (S)-(-)-tricyclic ketone Ill (55mg, 0.21 mmol) was heated at reflux in anhydrous toluene for 1 Omin. The mixture was allowed to cool to just below reflux, and a catalytic amount of ptoluenesulfonic acid was added. Reflux was resumed and continued for 20h. The mixture was allowed to cool to ambient temperature and concentrated. Purification by silica gel chromatography (eluting first with 100% ethyl acetate followed by 6:5:1 ethyl acetate/chloroform/methanol) afforded 12.5mg (15%) of the product as a bright yellow solid.Low resolution mass spectrometry shows parent ion (M+1) at 426 (calcd 426). 1H NMR (300, CDCI3): 60.87 (t, 3H, J=7), 1.85 (m, 2H), 5.22 (s, 2H), 5.42 (s, 2H), 6.60 (s, 1 H), 7.44 (s, 1 H), 7.62 (m, 6H), 8.67 (d, 1 H, J=6), 9.60 (s, 1 H).

Pharmaceutical formulations (A) Transdermal System Ingredients Amount Active compound 600.0 mg Silicone fluid 450.0 mg Colloidal silicone dioxide 25.0 mg The silicone fluid and active compound are mixed together and the colloidal silicone dioxide is reacted with to increase viscosity. The material is then dosed into a subsequently heat sealed polymeric laminate comprised of the following: polyester release liner, skin contact adhesive composed of silicone or acrylic polymers, a control membrane which is a polyolefin (e.g. polyethylene),polyvinyl acetate or polyurethane, and an impermeable backing membrane made of a polyester multilaminate. The system described is a 10 sq. cm patch.

(B) Oral Tablet Ingredients Amount Active compound 200.0 mg Starch 20.0 mg Magnesium Stearate 1.0 mg The active compound and the starch are granulated with water and dried.

Magnesium stearate is added to the dried granules and the mixture is thoroughly blended. The blended mixture is compressed into a tablet.

(C) Suppository Ingredients Amount Active compound 150.0 mg Theobromine sodium salicylate 250.0 mg Witepsol S55 1725.0 mg The inactive ingredients are mixed and melted. The active compound is then distributed in the molten mixture, poured into molds and allowed to cool.

(D) Injection Ingredients Amount Active Compound 20.0 mg Buffering Agents q.s.

Propylene glycol 0.4 Water for injection 0.6 mL The active compound and buffering agents are dissolved in the propylene glycol at about 50"C. The water for injection is then added with stirring and the resulting solution is filtered, filled into an ampule, sealed and sterilized by autoclaving.

(E) Capsule Sngredients Amount Active Compound 200.0 mg Lactose 450.0 mg Magnesium stearate 5.0 mg The finely ground active compound is mixed with the lactose and stearate and packed into a gelatin capsule.

Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

Claims (12)

Claims

1. A compound of formula (I)

wherein R is hydrogen, alkyl, alkenyl or phenyl; Q is hydrogen, halogen, cyano, 5-tetrazolo, -COOR3, -CONR4R5, -C(NH2)=NR6, -CH=NNH2, -(CH2)nR7, -CH=CH(CH2)nR7 or -C~C(CH2)nR7 wherein n is 0, 1, 2 or 3; R3 is hydrogen or alkyl; R4 and R5 independently represent hydrogen, alkyl, aminoalkyl or dialkylaminoalkyl; R6 is hydrogen, alkyl, hydroxy, alkoxy or -COOCH2NHCOOtBu; R7 is hydrogen, hydroxy, -NR1 R2, -NHCOR8 or a nitrogen heterocycle of formula

wherein R1 and R2 independently represent hydrogen or alkyl; R8 is alkyl or Alkyl; Y is O, S, NR9, CH2 or a direct linkage; R9 is hydrogen or alkyl;T is hydrogen or when Q is halogen T may also represent halogen; and X is a free electron pair, oxygen or alkyl; and pharmaceutically acceptable salts thereof.

2. The compounds qf Claim 1 wherein R is methyl, ethyl or phenyl.

3. The compounds of Claim 2 wherein X represents a free electron pair.

4. (S)-(-)-l 1 -Aza-1 0-carboxamidoxime-7-ethylcamptothecin and pharmaceutically acceptable salts thereof.

5. The compounds of Claim 1 in the R configuration.

6. The compounds of Claim 1 in the S configuration.

7. A pharmaceutical preparation comprising a compound of Claim 1 and a pharmaceutically acceptable carrier.

8. A method of inhibiting topoisomerase I enzyme comprising contacting said enzyme with an effective topoisomerase I inhibitory amount of a compound of Claim 1.

9. A method of treating a tumor in a mammal comprising administering to said mammal, an antitumor effective amount of a compound of Claim 1.

10. A compound of Claim 1 wherein the E ring is open.

11. A compound of the formula (II)

wherein R* is methyl or ethyl Q1 is bromine and T is hydrogen or bromine.

12. A process for preparing a compound of formula (I) as defined in Claim 1 or a pharmaceutically acceptable salt thereof which comprises: (A) for the preparation of compounds of formula (I) wherein Q is hydrogen or halogen and R is other than hydrogen reacting a compound of formula (II)

wherein Q1 is hydrogen or halogen, preferably bromine, and Rt is alkyl, alkenyl or phenyl, with a tricyclic ketone of formula (III)

or (B) for the preparation of compounds of formula (I) wherein Q is hydrogen or halogen and R is hydrogen reacting a compound of formula (Ill)

with a compound of formula (l)()

wherein Q1 is hydrogen or halogen; and if necessary and/or desired subjecting the compound thus obtained to one or more further reactions comprising: (i) converting the resulting compound of formula (I) or a salt or a protected derivative thereof into another compound of formula (I) and/or (ii) removing any protecting group or groups and/or (iii) converting a compound of formula (I) or a salt thereof into a physiologically acceptable salt thereof.