AU601257B2

AU601257B2 - 5'-protected nucleoside phosphonites and process for their preparation

Info

Publication number: AU601257B2
Application number: AU11384/88A
Authority: AU
Inventors: Joachim Engels; Alfred Jager
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1983-09-06
Filing date: 1988-02-08
Publication date: 1990-09-06
Anticipated expiration: 2004-09-05
Also published as: ATE38839T1; AU1138488A; DK131591A; ES8505384A1; CA1235079A; JPS6072899A; JPH0662662B2; DK131691D0; DK166585C; EP0136543A2; PT79172A; DK131691A; DK162895B; DK424784A; DK131591D0; DE3475307D1; DE3332068A1; EP0136543B1; GR80287B; ES535627A0

Abstract

1. Claims for the contracting states : BE, CH, LI, DE, FR, GB, IT, LU, NL, SE A process for the preparation of deoxyribonucleoside phosphonates of the general formula I see diagramm : EP0136543,P14,F1 in which T denotes a protecting group for a primary hydroxyl group, B denotes a nucleoside base radical in which any exoamino group present is protected, G denotes a protecting group for a secondary hydroxyl group, Z denotes oxygen, sulfur or selenium and R denotes alkyl having up to 8 C atoms, cyclohexyl, benzyl, or phenyl which is optionally substituted by fluorine, chlorine, bromine, lower alkyl, lower alkoxy or trifluoromethyl, characterized in that a difunctional phosphonylating reagent of the general formula II see diagramm : EP0136543,P14,F2 in which X denotes chlorine or Y and Y denotes a group of the formula see diagramm : EP0136543,P14,F3 R**1 and R**2 representing identical or different alkyl or cycloalkyl radicals having up to 8 C atoms, or phenyl radicals, or R**1 and R**2 , together with the nitrogen, representing a saturated or unsaturated heterocyclic ring which can contain further hetero atoms, being reacted with a nucleoside of the general formula III see diagramm : EP0136543,P14,F4 in which T and B have the meanings given above, the resulting compound of the general formula IV see diagramm : EP0136543,P14,F5 being reacted with a compound of the general formula V see diagramm : EP0136543,P15,F1 in which B and G have the meanings given above, and the resulting compounds of the general formula VI see diagramm : EP0136543,P15,F2 in which T, R, B and G have the meanings given above, being oxidatively converted to compound of the general formula I. 1. Claims for the contracting state AT A process for the preparation of deoxyribonucleoside phosphonates of the general formula I see diagramm : EP0136543,P15,F3 in which T denotes a protecting group for a primary hydroxyl group, B denotes a nucleoside base radical in which any exoamino group present is protected, G denotes a protecting group for a secondary hydroxyl group, Z denotes oxygen, sulfur or selenium and R denotes alkyl having up to 8 C atoms, cyclohexyl, benzyl, or phenyl which is optionally substituted by fluorine, chlorine, bromine, lower alkyl, lower alkoxy or trifluoromethyl, characterized in that a difunctional phosphonylating reagent of the general formula II see diagramm : EP0136543,P16,F1 in which X denotes chlorine or Y and Y denotes a group of the formula see diagramm : EP0136543,P16,F2 R**1 and R**2 representing identical or different alkyl or cycloalkyl radicals having up to 8 C atoms, or phenyl radicals, or R**1 and R**2 , together with the nitrogen, representing a saturated or unsaturated heterocyclic ring which can contain further hetero atoms, being reacted with a nucleoside of the general formula III see diagramm : EP0136543,P16,F3 in which T and B have the meanings given above, the resulting compound of the general formula IV see diagramm : EP0136543,P16,F4 being reacted with a compound of the general formula V see diagramm : EP0136543,P16,F5 in which B and G have the meanings given above, and the resulting compounds of the general formula VI see diagramm : EP0136543,P17,F1 in which T, R, B and G have the meanings given above, being oxidatively converted to compound of the general formula I.

Description

S~zns- ture of App~icant LOD..ED AT SU"''C or See) of cmayand signature 8f FEB 1988 preseribed by M its Articles of Association. Meb u n

BY

(James Mrray COMMONWEALTH OF AUSTRA 6 y 0 5 '7rmi PATENTS ACT 1952.69 COMPLEETE

SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted; *Priority: Re lated Art: Published: 1.~ amC2-~ Name of Applicant: Address of Applicant Actual Inventor: Addre.ss for Service: HOECHST AKTrIENGESELLSCHAFT 45 Bruningstrasse, D-6230 Frankfurt/Main 80, Federal Republic of Germny JOACHIM ENGELS and ALFRED JAGER EDWD. WATERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: NUCLEOSIDE PHOSPHONITES AND PROCESS FOR THEIR PREPARATION The following statoment is a full description of this invention, including the best method of performing it known to US Signature. To: THE COMMISSIONER OF PATENTS.

HOECHST AKTIENGESELLSC AFT WATERMARK PATENT TRADEMARK ATTORNEYS -2- HOE 83/F 178 Non-ionic analogs of deoxyribonucleic acids (DNA) are important for the investigation of DNA-DNA and DNAprotein interactions. Of particular interest are phosphonic acid esters of deoxyribonucleotides as a result of 5 their chemical stability and on the basis of their capability to enter into cells and their high resistance to cell S C nucleases. Hitherto, four different strategies have been S described for the synthesis of methylphosphonate analogs of nucteotides: 10 1. Ogilvie et al. Nemer and K.K. Ogilvie, Tetraf c' hedron Lett. 21, Page 4149 (1980)) prepared a completely protected uridyt-3',5'-uridine methylphosphonate by Michaelis-Arbuzov rearrangement of the corresponding phosphite intermediates. This reaction (methyl iodide, 20 hours at 50 0 C) might not be generally applicable as a result of its drastic conditions, because, for example, methylation of the purine bases is to be expected.

2. Ts'o et at. Miller, J. Yano, E. Yano, C. Caroll, K. Jayaraman and P.O.P. Ts'o, Biochemistry 18, 5134 (1979); Proc. Natl. Acad. Sci. USA 78, 1537 (1981); P.S. Miller, N. Drean, S.M. Pulford and K.B. McParland, J. Biol. Chem. 225, 9659 (1980)) developed a synthesis strategy which is analogous to the phosphotriester method in oligonucleotide synthesis. Here, a protected nucleotide 3-0-ethylphphosphonic acid -cyanoethy ester is used as the most important intermediate. This method has the Y- i L.i-Y- ~~~IXIIWI*CI~~

I

3 known advantages and disadvantages of the phosphotriester method, the low reactivity of the phosphorus(V) compound being mentioned in particular as a disadvantage.

3. Agarwal et at. Agarwal and F. Riftina, Nuct.

Acid Res. 6, 3009 (1979)) used methylphosphonic acid dichloride as a difunctional phosphonylating agent. In the second step, the chloride has to be activated by means of tetrazole, The crude product obtained can only be a* purified by efficient chromatography.

10 4. J. Engels and A. Jager, Angew. Chem. Suppl. 1982. 2010, and N.D. Sinha, V. Grossbruchhaus and H. Koster, Tetrahedron Lett. 24, 887 (1983) used methyldichlorophosphane as the starting material. The Latter authors synthesized 0 the nucleotide methylphosphonates on a polymeric support.

0 15 The products obtained are yet to be characterized.

Whereas the reactivity of the second halogen of methylphosphonic acid dichloride is generally too Low and additional activation is necessary, the activity in the case of phosphinic acid dichlorides is if anything too high. Thus, handling difficulties arise (extremely anhydrous medium) and, in addition, the symmetrical phosphonous acid ester is unavoidably formed.

By contrast, the present invention relates to a process for the preparation of deoxyribonucleoside phosphonates of the general formula I i- n~ i- "1 -4-

B

T-O

V

Z=P R 0 IB oo

G-O

in which d T denotes a protecting group for a primary hydroxyl as S group, preferably triphenylmethyl Tr), p-anisoyldiphenyLmethyL or di(p-anisoyL)phenylmethyL, B denotes a nucleoside base radical in which any exoamino group present is protected, preferably 1thyminyl, 1-(N-4-benzoycytosinyL), 9-(N-6-benzoyladeninyl) or 9-(N-2-isobutyroylguaninyl), G denotes a protecting group for a secondary hydroxyl group, Z denotes oxygen, sulfur or selenium and R denotes alkyl having up to 8 C atoms, cycLohexyl, benzyl,or phenyl optionally substituted by fluorine, chLorine, bromine, Lower alkyl, lower alkoxy or trifluoromethyL, and preferably denotes methyl, ethyl, phenyl or benzyl, especially methyl, wherein a difunctional phosphonylating reagent of the general formula II

X

Y

(II)

wherein X denotes chlorine or Y and Y denotes a group of the formula

R

1

-N

SR

2

R

1 and R 2 representing identical or different alkyl or cycloalkyl radicals having up to 8 C atoms, or phenyl radicals, or R1 and R2, together with the nitrogen, representing a saturated or unsaturated heterocyclic ring which can contain further heteroatoms, is reacted with a o o nucleoside of the general formula III 0 6 ta ta T-o- O\ (III) AH II-O wherein T and B have the meanings given above, preferably

B

0 0 R -P y is reacted with a compound of the general formuLa V G-0 wherein B and G have the meanings given above, preferabLy at -20 to +100°C, in particular at room temperature, and the resulting compound of the general formmua VI the resulting compound of the general formiula VI 6

B

TO

0 I

I

R-P B

(VI)

i G-O 4 4 *9le# wherein T, R, B and G have the meanings given above, is oxidatively "onverted to compounds of the general formula 1, preferably at -80 to +100C, in particular at -20 0 C to room ,5 temperature.

Sand form the subject of the present invention, as does the 4 method for their preparation.

In principle, the radical R in the difunctional phosphonylating reagent of the general formula II can be any non-cytotoxic organic radical which is inert towards the compounds of the general formulae II to VI and which does not hinder the reactions.

Examples of possible groups of the general formula

-NR

1

R

2 are: dimethylamino, diethylamino, diisopropylamino, methylethylamino, methylpropylamino, methylhexylamino, methylcyclohexylamino, methylbenzylamino, morpholino, pyrrolidino, piperidino, methylanilino, diphenylamino, imidazoli, triazolo, benzotriazolo and tetrazolo.

The starting materials of the general formula II S :E B(12.43)

T*.

4r '14 7

H-NR

1

R

2

(VII)

in which R and R 2 have the meanings given above.

Correspondingly, compounds of the general formula II in which X denotes a group of the formula Y are accessible by further reaction with the same secondary amine or a different secondary amine of the general formula VII. The compounds of the formula II can be purified by vacuum distillation.

The reaction of the phosphonylating reagent of the general formula II with a suitably protected nucleoside of the general formula III is carried out in a moderately polar solvent, preferably chloroform, with the exclusion of moisture. Tertiary amines, preferably ethyldiisopropyli, amine (lunig's base), can be used as auxiliary bases for this reaction. Working-up is carried out by aqueous extraction and precipitation of the products of the general formula IV with a non-polar solvent such as petroleum ether or pentane. The phosphonous acid ester-amides of the general formula IV obtained in this way precipitate as colorless powders and can be characterized by spectroscopic data such as 1H-NMR, 3 1 P-NMR or UV and elementary analysis. Furthermore, they can also be converted, by direct oxidation, to the phosphonic acid ester-amides of the general formula VIII T O 6 Z P -R

I

(VIII)

ii t 8 T, B, Z, R and Y having the meanings given above, which can then be isolated and characterized.

Remarkably, no symmetrical dinucleoside 3',3phosphonite is formed within the limit of detection.

As shown by 3 1 P-NMR, the compounds of the general formula IV are stable for at Least 1 month in powder form, when stored dry and at a maximum of -20 0 C. This great stability of the phosphonous acid ester-amides is astonishing and emphasizes the value of this method. Its universal applicability in the synthesis of phosphonic e .acid diesters of nucleosides is shown by the reaction with 9, suitably 3'-protected nucleosides: ,t In this reaction, the 5'-protected nucleoside phosphonites of the generaL formula IV are dissolved in a moderately polar solvent, preferably acetonitrile, chLoroa 4I t form or tetrahydrofuran, and mixed with the nucleoside of 0 the general formula V (protected in the 3'-position).

Suitable protecting groups G in the compounds of the general formula V are acyl groups such as benzoyL, acetyl, S 20 pivaloyl or levulonyl, or silyl groups such as t-butyl- 4 dimethylsilyl. The reaction is catalyzed by an acid, preferably an azole or amine hydrochloride. Benzotriazole is particularly suitable. It is remarkable that HPLC analysis of the product shows no symmetrical and only traces of the 3',3'-isomeric phosphonate.

The labile intermediate, namely the phosphonous acid triester of the general formula VI, is oxidized directly to the phosphonate of the general formula I. In addition to the oxidizing agents usually employed for this 1 *1 s :lili

'I

4II 444( 9 purpose, such as dinitrogen tetroxide or iodine, peroxides, in particular anhydrous t-butyl hydroperoxide, have proved valuable. The reaction is preferably carried out in a moderately polar solvent, particular preference being afforded to acetonitrile or chloroform. Particular consideration should be given to the known acid-catalyzed transesterification of the diacylalkylphosphonites (F.W.

Hoffmann, R.G. Roth and T.C. Simmons, J. Amer. Chem. Soc.

5937 40 (1958)).

The compounds (some of which are already known) are characterized by means of 31P-NMR and 1 H-NMR and also chromatographic comparisons with authentic material.

The compounds of the general formula I in which Z denotes sulfur or selenium are prepared by direct reaction of the compounds of the general formula VI with elemental sulfur or selenium. Stirring with the stoichiometric quantity of sulfur or selenium, in a polar solvent such as tetrahydrofuran, leads to good yields of the corresponding thiophosphonates or selenophosphonates of the general 20 formula I. Characterization is carried out by means of 3 1 P-NMR and 1H-NMR as well as elementary analysis.

Because of the presence of a center of asymmetry in the nucleoside moiety and the production of another on the phosphorus, the phosphates of the general formula I exist as mixtures of diastereomers (see Table 6, isomers 1 and 2).

The isomer ratio, which is close to the statistical ratio of 1:1, is only very slightly influenced by a variation in the parameters such as the solvent, the temt t ti 4 *1

__I

perature and the sequence of addition.

Preparation of a compound of general formula IV is described in Examples 1 and 2. Properties of various examples of compound of general formula IV are given in Table 2. The other examples and tables are included for reference to the parent invention.

4 t 4. rz Example 1: Starting material 11 3 C-P[N(CI 3 2 2 In a 1000 ml three-necked flask fitted with a dropping funnel and a mechanical stirrer, 125 ml (1.9 mol) of dimethylamine are introduced into 400 ml of anhydrous diethyl ether and reacted, over a period of 60 minutes, with a solution of 60 ml (0.40 mol) of methyldichlorophosphane in 200 ml of anhydrous ether, Suwhile cooling with ice. After stirring for 2 hours at Sroom temperature and for 1 hour at 50 0 C, the precipitate S ,is filtered off under a protective gas and rinsed twice w th 100 ml of ether and the filtrate is concentrated at about 0.1 bar. The remaining residue is rapidly distilled over at 0.5 bar/124 0 C. Precision distillation with a Vigreux column (50 cm) at 64-65 0 C/65 mbar gives 36.6 g (66% of theory) of a colorless liquid.

Analysis: C 0.2% 3 1 P-NMR (TIF) =87 ppm 1 1-NMR (CDC 3 S 1.23 ppm 711z, P-CII 3 2.66 ppm 711z, N(Ct 3 2 E" Example 2: The 5'-tritylnucleosides III (1 mmol) are dissolved in 6 ml of anhydrous chloroform under an inert nitrogen atmosphere and I 3

CPEN(CH

3 2 2 (2 mmol) is added. The reaction is complete after 12 hours at room temperature (stirring) or after only 2 hours if catalytic quantities (0.1 mmot) of collidine hydrochloride are added.

11 The solution is then transferred with 100 ml of methylene chloride to a 250 ml separating funnel and extracted twice by shaking with 50 ml of saturated sodium chloride solution (containing 0.1 ml of triethylamine).

The organic phase is dried over anhydrous sodium sulfate and concentrated to a foam. This is stirred for 2 hours with 50 ml of pentane. The residue is filtered off and dissolved in 2 ml of diethyl ether and the solution is slowly added dropwise to 50 ml of thoroughly stirred pentane. The fine precipitate is filtered off and dried to give an 85-95% yield of the compound of the general formula IV (Tables 2 and 3).

a The compounds can be identified directly by c31P nuclear magnetic resonance spectroscopy or, after oxidation with t-butyl hydroperoxide, as phosphonic acid ester-amides of the general formula VIII (Tables 4 and t In the 31P-NMR spectrum, these substances show up to 3% of hydrolyzed product (nucleoside methylphosphinate), but no detectable quantity of symmetrical dinucleoside 3',3'-phosphonited This demonstrates the superiority of the method compared with former methods, which always yielded about 5-10% of these products. When stored as dry powders at -20 0 C, no decomposition can be observed within a month.

The following reagents were also employed analogously: N (C 2

H

5 2 1 3 C 1 12- S N LC i (C 2-72

H

3 C 2 \Cl C H 'Cl C Example 3: The 5'-tritylnucleoside III (1.00 mmol) and 1.71 ml (10 mmol) of N,N,N-ethyldiisopropylamine are introduced into 6 ml of THF, and 2.00 mmol of phosphonyla- Sting agent II are then slowly added dropwise. After stirring at room temperature overnight, the reaction solution is added dropwise to ice-cold water (50 ml, saturated with NaCI). After extraction with twice 20 ml I 10 of methylene chloride, the organic phase is dried with sodium sulfate and the solvent is removed in vacuo.

Further purification is carried out by precipitation as above (Tables 2 and 3).

Example 4: h The product of Example 3, 3'-0-Benzoylthymidine (0.20 mmol) and l-H-benzo-triazole (0.80 mmol) are dried in a round-bottomed flask and then dissolved in 1.0 ml of dry acetronitrile. The reaction is complete within one minute, a very air-labile and acid-labile phosphonite VI being formed; this is converted directly to the phosphonates I, with 80-90% yield, by oxidation with anhydrous t-butyl hydroperoxide (0.25 mol) (according to H. Langhals, E. Fritz and J. Mergelsberg, Chem. Ber. 113, 3662 (1980) dissolved in 13 acetonitrile or tetrahydrofuran.

Alternatively, 30 mg (0.95 mmol) of sulfur are added to 0.7 mmol of VI at -20 0 C and the mixture is stirred overnight at room temperature. The reaction is generally already complete after a few hours. 20 ml of Ichloroform are then added and the organic phase is extrac- Sted three times by shaking with water. After drying over sodium sulfate and removal of the solvent, a crude product Sis obtained which is purified by silica gel chromatography to give the compound I in 80-90% yield (Table 6).

Alternatively, 118 mg (1.5 mmol) of black selenium I are added to 0.7 mmol of VI and the mixture is stirred overnight. After working-up (as above), the compound I is obtained in 60% yield (Table 6).

HPLC analysis of the reaction mixture (in the case where Z 0 by comparison with the authentic reference, P.O.P. T'so et al., Biochemistry 18, 5134 (1979)) showed about 1% of the 3',3'-ospsphonates and no TABLE 1: Compounds CII) H 3

C-PXY

1 H-NMR (CDC[ cfCppm) 31

P-NMR

g(ppm)a) B.p.

0 C/bar

P-CH

3 Other protons CL CH 141.2 44-47/10 1.61 7.41-7.18 3. -Nz 7 Id J13.1 Hz) Cm, 5H, aromatic H,d J=8.3 Hz)) CL -NC 6

H

5 2 132 2 b) 92-44/10-8 1.53 7.5-6.9 d J=14 Hz) 10 H, aromatic H) -N

\N

N

Nttw CNy1O 2

NPJ-NL

62 c) 72 c) 91 c) 81 d) 92/10-5 CM.p.: 60 0

C)

110 0

C)

2.20 d(J=10 Hz) 2.32 d(J=9 Hz) 2.49 d(J=9 Hz) 2.60 d(J=9 Hz) 7.45 Cs, 2H) 6.95 Cs, 4H) 8.51 Cs, 2H) 8.07 Cs, 2H) 8.89 Cs, 2H) 8.88 Cs, 2H) a) reLative to 85% H 3

PO

b) 1,2-dichoroethane c) THF d) dioxane .i I -ew TABLE 2: Compounds (IV)Th TrO -Q 0 1I 1 2

H

3 C- -NR R 1 H-NMR CCDCL 3 Ifppm) b) P-C

H

3 R R 2 31 P-NM~R, s(ppm)a) C1 2- d ich Lo r oet h an e CH 3 N R 1R2 C H 3 C H 3 139.61-140.7 7.60/7.57 1.44/1.43 1.16/1.14 2.76/2.47 CS) d(J=1.2 Hz) dCJ=7.3/7.0 Hz) dCJ=8.9 Hz), N(CH3) 2 C 2 H 5 C 2 H 5 137.3 7.59/7.57 1.41/1.40 1.18/1.16 1.04/0.91 (dCJ=7.0 Hz), dCJ=1.2 Hz) d(J=1.2/.0.Hz) dCJ=7.6 Hz) NC2 H 5 2.76-3.09 Cm, seL., compLex) -NCCH 2 CH 3 2 CHC(CH 3 2 CHC(CH 3 2 -120.4 dCJ=1.2 Hz) 1.37/1.36 dCJO0.9 Hz) 1.18/1.13 dCJ=8.5/7.9 1.13/1.07/1 .04/0.98 Hz) d(J= 6.7 Hz), NECHCCH 3) 2] CH 3 C6 H 5- 134.7/- 136.2 7.51/7.50 1.40/1.38 1.33-1.31 3.02/2.86 3 6 dCJ1.2 Hz) dCJ1.3/0.9 Hz) dCJ8.8 Hz) dCJ3.4 Hz), N-CH 3 C 6H 5 C6 H 5- 130.3/128.6 7. 39/7. 47 dCJ=1.2 Hz) 1.40/1.36 1.15/1.10 dCJ=1.2/0.9 Hz) dCJ=9.8 Hz) a) relative to 85% H 3 PO 4 b) relative to TMS TABLE 3: Compounds (IV) T-ol C' 0

H

3 C- P-N (CH 3 )1 H-NMR (CDCL 3 cf~ppm) d) Ta) Bb) 31 P-NMR, cf(Ppm) c) H-8 H-2 OCH 3 P- H3 2 P-H3 1,2-di chLor-oethane MMTr Ad Bz -145.3 8.73/8.72 8.19/8.16 3.76/3.75 2.67/2.25 1.20/1.19 d 0=8.8 Hz) d C0=7.3 Hz) DMTr raz -146.2/145.8 0 DMTr G1B -144.8 a) MMTr =monomet.hoxytr-iphenyLmethyL~p-,anisoyLdiphenyLnethyL) DMTr dimethoxytriphenyLmethyL~di(p-anisoyL)phenyLmethyL) b) Ad Bz 9-(N-6-benzoytadeiinyL) C Bz= 1-CN-4-benzoyLcytosinyL) G i 9-CN-2-iSobutyroyLguaninyL) 0) reLative to 85% H 3 PO 4 d) reLative to TMS TABLE 4: Compounds MVIDI o 4*t 4 0 4 4 6 5 6 4 4 0 644 0Th 1 H-NMR(CDCL X(- 11 R R (1,2-dichloroethane) A~max (Log E) H 6 P HR 1 3 C:MR NRpmf RV(HO)1 CH 3 40 263 nm 7.60/7.50 1.38/1.40 1.41/1.38 2.65/2.49 N(CH 3 2 d~jzl6.2 Hz) (d,J=9.5 Hz)

C

2

H

5 -39.

5 c) 264. nm (4.00) 7.52 1.42 1. 3f. 0.94 (t,Jx7.1 HN) d~l.2 Hz) d1j=16.5 Hz) d[J=0.9 Hz) -N(CH 2 CH 3 2 2.8-3.1 m, N(C 2H 5)2 C 2 H 5 39 5 d) 264 nm (3.98) 7.59 1.38 1.36 1.07 (t,J=7.0 Hz) d(J=1 .2 HzO d[J=76.5 Hz) HC 2

H

5 2 3.05 (dq, J=10.7 Hz) JCH 2CH 3=7.0 Hz

NCC

2 H 5 2 CH(CH 3) -38 264 nm (3.97) 7.53/7.57 1.36 1.31 1.19/1.17/1.04 32d(J=16.2 Hz) (d,J=4.0/6.7/6.7Hz) NECH(CH 3 2 1 C H 33 5 c) 260. nm (4.09) 7.51 1.68 1.23 165 uppo~* e) (d,J=1.2 Hz) d[J-16.8 Hz) (S)

CH

5 -30.4c) 260 nm (4.08) 7.48 1.59 1.34.

Lower a) relative to 85Z H 3 PO 4 b) reLative to TMS c) .1/2 H 2 0 ()dlJ-17.7 Hzl (S) d) anhydrous e) isomers separated, relative mobiLtty.in TLC (e:hiyL acetate/methanol 100:4) L 5: Co po nd 4 CH

B

31 r. C)0=P- (H-NR(CC)(Pm b) 3 P-NMR, Jkppm) cCDC 3 B B 2 dichLoroehane UV (CH OH) H -8 H 2 0 -CH 3 P-NCCH 3) P-CH3 MMTr. AdB -41 278 nm (4.39) 8.73/8.68 8.17/8.11 3.7613.75 2.66/2.64 1.23/1.20 230 nm (4.52) CS) Cs) CS) dJ8.9 Hz') dCJ=7.4 Hlz) MMTr Cz -41.1 O7 DMTr GB -41.4 as for Table 3 TABLE 6: Compounds (I) 0 Tay Thy 31 P-NMR, A'(ppm)a) X 1,2-dich~oroethane UV(CH 3 OH) Nmax (Log E) Zone b) 1

H-NMR,

-CH 3 CDCL 3 r -CH 3 J(ppm) C) p-CH.3 S -99/97.5 2I65 nm (4.25) upper 1.89 CTp) 1.43 (pT) 1.87 d(J=15.2 Hz) Lower 1.89 (Tp) 1.46 (pT) 1.80 CS) Cs) d(J=15.3 Hz) Se -107.5/ -105.5 1 37=860.Hz p=Se 264 n~m (4.26) upper Lower 1 .90 (Tp) d(J=1.2 Hz) 1 .98 CTp)

(S)

1 .42 (pT) d(j=l.1 Hz) 1 .46 CpT) (s) 2.04 d(J=14.2 Hz) 1.90 d(J=14.6 Hz) a) relative to 85%. H 3 PO 4 b) reLative mobility in TLC (ethyl acetate/methanol 100:4) c) re~Lative to TMS

Claims

1. 5'-protected nucl.eoside phosphonites of general formula T <0 T 0 I V o 0 R-P Y in which .o T denotes a protecting group for a prinary hydroxyl group, o B denotes a nucleoside base radical in which any exo-amino group present is protected, 4 t S.R denotes alkyl having up to 8 C atoms, cyclohexyl, benzyl or phenyl optionally substituted by fluorine, chlorine, bromine, lower alkyl, lower alkoxy or trifluoromethyl, Y denotes a group of the formula 0 R'1 -N 2 R R and R representing identical or different alkyl or cycloalkyl radicals having up to 8 C atoms, or phenyl radicals, or R 1 and R, together with the nitrogen, representing a saturated or unsaturated heterocyclic ring which can contain further heteroatoms. r -21-

2. A process for the preparation of 5'-protected nucleoside of phosphonates of the general formula IV as claimed in claim 1, wherein a diffunctional phosphonylating reagent of the general formula II 1Y X wherein X denotes chlorine or Y and Y is as defined in claim 1 is reacted with a nucleoside of the general formula III i (III) H-0 to obtain the resulting compound of the general formula IV B ST-.O R -P Y T. B, R and Y being as defined in claim 1. 1 DATED this 5th day of February 1988. t} HOECHST AKTIENGESELLSCHAFT EDWD. WATERS SONS SPATENT ATTORNEYS QUEEN STREET MELBOURNE. VIC. 3000.