DE1067810B - Process for the production of aldosterone and its derivatives - Google Patents

Description

, -ν

GERMAN

PATENT OFFICE

kl. 12 ο 25/05

INTERNAT. KL. C 07 C

C07J

far ". '/? °

-Γ if / '.'"R 24255 IVb / 12 ο

REGISTRATION DAY 23 OCTOBER 1958

NOTICE OF THE APPLICATION AND ISSUE OF THE EXPLAINING PAPER: 29th O CTO B E R 1959

Aldosterone, which is known to have a special effect on the electrolyte metabolism even in the smallest doses shows, is evidently in equilibrium because of its chemical behavior through the following standing forms:

CH ₂ OH

HO

AWAY

0

CHO CO

HO
-CH CO

CH ₂ OH

₀ CH ₂ OH
CH C-OH

procedure

for the production of aldosterone and its derivatives

Applicant: Dr. Tadeus Reichstein, Basel (Switzerland)

Representative: Dipl.-Ing. E. Splanemann, patent attorney, Hamburg 36, Neuer Wall 10

Claimed priority: Switzerland of November 6, 1957

Dr. Tadeus Reichstein, Dr. Albert Wettstein, Dr. Georg Anner, Dr. Jean-Rene Billeter,

Dr. Karl Heusler, Basel,

Dr. Robert Neher, Binningen,

Dr. Julius Schmidlin, Basel,

Dr. Hellmut Ueberwasser, Riehen,

and Dr. Peter Wieland, Basel (Switzerland),

have been named as inventors

CH ₂ OH .0

CO

The technical production of this highly effective hormone encountered considerable difficulties because, on the one hand, the amounts occurring in the adrenal glands are too small, larger amounts of aldosterone can be obtained economically in an extractive way, and on the other hand, it has not yet been possible to obtain aldosterone from others in the Producing naturally occurring steroids partially synthetically. It was therefore a great step forward when it was possible for the first time to build up this active ingredient in a totally synthetic way. The synthesis starting from a tricyclic compound containing rings A, B and C comprises more than 20 steps. The yields in the last stages of the synthesis mentioned above, which are shown in the following equation (I - * ■ III), have so far been unsatisfactory.

LiAlH,

-O.

OH CH ₂ OH O --- CH C. '

II

9j9 640/427

OH CH ₂ OH It was already known that of the two ketals

in the 3- and 20-position, which are derived from .d ⁴ -3,20-dioxo-21-acyloxy-pregnen compounds, the ketal

_N , ^ ^ group easier in 3-position, z. B. already with diluted

Hydrochloric acid ^ |; ₅ acetic acid, is cleavable. The cleavage of the 20-ketal

in these compounds, however, so far only succeeded with the help of mineral acids, eg. B. sulfuric acid, in aqueous Solvents such as aqueous methanol. Although this method is used in 18-unsubstituted pregnans ίο has been used with good success, it delivers aldosterone-3,20-diketalen very poor yields, since the free aldosterone is largely inactive due to mineral acids

A new process has now been found with which products are converted. It has now been found that the yield in the conversion of ketals is from that in the 3,20-di-type of the compound I obtained according to the process in aldosterone or aldosterone-15 ketals of the aldosterone ie ^ l-diacylate or -21- mono-21-ester can be increased several times over. Surprisingly enough, the new Verylate both ketal radicals are already carried out by simply heating a (18 -> - II) -lactone with aqueous carboxylic acids, in particular a Zl ^^ O-ßis-ialkylendioxyJ-ll / J ^ l- Dihydroxy-pregaliphatic carboxylic acids, for example aqueous formic 18-acid or its 21-ester, cleave the lactone group with acid, acetic acid, propionic acid, etc. Lithium aluminum hydride to (18 - + ■ ll ^ Cyclohemiacetal 20 The corresponding aldosterone-21-monoreduced result, the product obtained with an acylation aeylate in very good yield The 18-position acyloxy group, the protected oxo-O-acyl radical is hydrolyzed at the same time, can be liberated from groups in the 3- and 20-position by acid hydrolysis in diketals of 18,21-di-O-acyl or 21-O-monoacyl and optionally the 21 position acyloxy-25 aldosterone or mixtures of mono- and diacyl groups with alkaline saponification.

Used for the reduction of the lactone mentioned. The saponification of the aldo

one the lithium aluminum hydride in an amount that succeeds steron-21-moTioacylatc only under certain just sufficient to carry out the process-related reduction conditions with good yield, preferably with the help of Cyclohcmiacctal; it must contain 30 alkaline agents. But even if the fact that the free 21 permanent hydroxyl group is used is also used, the yield of pure aldosterone reacts under the hydroxyl group with the reducing agent under water - the 18-unsubstituted substance development similarly constructed for saponification. It is therefore advantageous to use ier 20,21-ketone under the usual conditions, unsatisfactorily, from about half to three quarters of a mole of lithium. Namely, it has been found that also u nterminium hydride per mole of lactone. ' The reaction product 35 can, surprisingly, be isolated in the usual way under tired conditions at the Aldosterort and with reaction wise * an isomerization occurs at carbon atom 17, capable derivatives of carboxylic acids, e.g. B. Acid anhy- To achieve high yields in the saponification of three or acid halides, in the presence of an acidic aldosterone-21-monoaeylate, it is therefore necessary to convert a binding agent such as pyridine. to choose the conditions so that although the saponification is particularly advantageous, it is as complete as possible in the reduction 40, but on the other hand the isomerization with lithium aluminum hydride is avoided. This is achieved above all by a direct reaction with an acid anhydride or halide to shorten the otherwise usual reaction time. They acylate, since the formation of undesired secondary _{substances is largely avoided, depending on the p u of} the reaction medium and products. In this way the reaction temperature. At temperatures of 15, the 18,21-diacylates are obtained in very good yield. 45-25 ° C are sufficient for \ ^r SE OF alkali metal in these compounds is the I8ständige acyloxy carbonates only a few minutes in a homogeneous solution, group extremely easily saponifiable, z. B. even when using Alkdimetallbicarbonaten some by heating with aqueous solvents, hours.

such as acetone, methanol, etc. The starting materials for the process are from the

For the method and according acylation can be racemic or optically active 50 (18 - + - ll) lactones reactive derivatives of saturated or unsatu- the <l ⁴ -3,20-dioxo-ll ^, 21-dihydroxypregnen-18-oic acid. in ten aliphatic or cycloaliphatic) !, by aroma in a manner known per se with the help of 1,2- or 1,3-tables, araliphatic or heterocyclic carbon glycols, z. B. use ethylene glycol, 1,3- or 1,2-propylene acids; For example, formic acid, glycol, in the presence of an acidic catalyst be-acetic acid, trifluoroacetic acid, propionic acid, which rides butter.

acids, valeric acids, such as n-valeric acid or tri-die obtained by the process according to the invention

methyl acetic acid, of caproic acids, such as / 3-trimethyl-18,21-diacylates and 21-monoacylates of aldosterone propionic acid, the Oenanth-, Capryl-, Pelargon-, Caprine-, 3,20-bis-alkylcnketals are new. They represent racemic Undecyl acids, e.g. B. Undecylenic acid, the lauric, or optically active compounds. They form worth myristic, Palmitic or stearic acids, e.g. B. the oil - 60 full intermediates for the production of the corresponding acid, the Ci'clopentyl-, Cyclohexyl- or Phenylessig- the aldosterone-21-monoacylate and the free aldoic acids or propionic acids, benzoic acid, hexasterones.

hydrobenzoic acid, furan-2-carboxylic acid, nicotine- The claimed process also includes execution acids, furthermore dicarboxylic acids, such as oxalic and amber forms, in which only part of the process measures or glutaric acids, of substituted carboxylic acids, such as 65 and these optionally in other Reüieniolge by - /? - ketocarboxylic acids, z. B. the acetoacetic, propionyl acetic acid, or where one of one in any Butyrylacetic acid or caprinoyl acetic acid or intermediate product obtainable from amino process stage starts out acids. In the acylation, the corresponding process steps and the remaining process steps are obtained. 18,21-diacylates and 21-monoacylates of the aldosterone- The invention is described in more detail in the examples.

3.20 diketals. 7 ° The temperatures are given in degrees Celsius.

b 6

Example 1 · Fraction 13 + 14 ...... ether-ethyl acetate (99: 1):.

Fraction 15 + 16 ether-ethyl acetate (95: 5)

A solution of 893 mg of the (18 -> ■ U) -lactone fraction 17 + 18 ether-ethyl acetate (75:25)

the d, lJ ⁵ -3,20-bis-ethylenedioxy-ll ^, 21-dihydroxy-pre-fraction 19 + 20 ether-ethyl acetate (50:50)

gnen-18 acid in 50 cm ^{3 of} tetrahydrofuran (with lithium 5 With fractions 1 to 8 only traces of aluminum hydride can be dehydrated and distilled), amorphous substance is removed. The residues of the fraction with stirring in a dry nitrogen atmosphere inside 9 to 16 crystallize when absorbed in ether for half 15 minutes 3.35 cm ³ 0.40 m lithium aluminum and contain the main amount of the material used, hydride solution in tetrahydrofuran and stir that you become first individually from ether with methylene mixture 3 _^3/4 hours then at 20 to 23 °. io chloride as a solubilizer fractionally uinkrystallisiert. The reaction mixture is then cooled with ice. Fractions 9 and 10 are thus obtained in total a mixture of 13.4 cm ^{3 of} 1 m potassium sodium tartrate 32.3 mg of 18.21 diacetate in fine, colorless sticks of the solution and 2.7 cm ³ 0.5 n-tartaric acid poured out, the m.p. 200 to 206.5 °. IR absorption in CH ₂ Cl ₂ : no tetrahydrofuran distilled off in vacuo and the back- (O - H); 5.75 µ (ester-C = O); 9.04 μ (ketal), permanent aqueous suspension several times with methylene. When the 18,21-diacetate is dissolved in methylene chloride, the chloride is extracted. The extracts are washed with 1 m of subsequent filtration and recrystallization from hot potassium sodium tartrate solution and water, acetone is already combined, dried and evaporated as a result of the ingress of water. The residue partially undergoes hydrolysis to give 21-monoacetate (see below). is colorless and quickly becomes when taken up in ether. Fractions 12 to 15 can be completely solidified in the above. Mentioned for determining the degree of conversion "o manner a total of 28.1 mg of pure 21-monoacetate, a sample of the crude product (5.00 mg) was investigated in the infrared in colorless, bevelled at the ends of the prisms from the spectrometer, and the intensity of the still double-melting point Isolate 182.5 to 186 ° / 198.5 to 201.5 ° existing lactone C = O absorption band at 5.65 μ. Recrystallization from hot acetone changes compared to that determined for pure Dikctal. not the melting point. IR absorption in CH ₂ C1 ₂ : 2.79 Based on the integration values found, it is 25 to 2.89 μ (O - H); 5.73 µ (ester-C-O); 9.05 μ portion of unreacted starting material about 4 ° / _c . (Ketal).

927 mg of the above crude product are obtained from methylene.

chloride tetrahydrofuran a small top fraction of the mixed anhydride of formic acid and acetic acid

d, lJ ⁵ -3,20-bis-ethylenedioxy-ll, 18; 18,21- (bis-oxido) -pre- acid, of propionic anhydride, trimethylacetic acid-

gnens in the form of colorless, overgrown needles of 30 chloride, cyclopentylpropionic acid chloride, phenylpropionic

M.p. 265 to 267 °. The IR absorption spectrum in acid chloride or succinic anhydride is obtained in

Methylene chloride solution is in the hydroxyl and double completely analogous way the 18,21-di- or 21-formate,

binding area practically empty. The acetylation of -monopropionate, -Trimcthylacetat, -Cyclopentylpropio-

Mother liquor with pyridine and acetic anhydride and nat, -phenylpropionate, -hemisuccinate of aldosterone-

Working up, as indicated in Example 2, gives a 35 3,20-diketal.

Mixture of the 18,21-di example 3 described in the following example and the 21-monoacctate diketal.

The d, l-21-0-acetyl-aldosterone can be obtained as follows

^Beis P ' ^{el 2} nen:

223 mg of the (18 - * - ll) -lactone of the d, l- / J ^s -3,20-bis- 40 a) From pure 18,21-di-O-acetyl-diketal: 10.66 mg of the ethylenedioxy -ll be ?, 21-dihydroxy-pregnene-18-oic acid /, in example 2 diacetate and described ^a 1.0 cm as described in example 1, reduced in tetrahydrofuran at 90 ° / ₀ acetic acid are in a nitrogen atmosphere lithium aluminum hydride. After 15 minutes, heated in a 125 ° oil bath. The reaction is mixed with the solution with 4.75 cm ^{5 of} acetone reaction solution, after cooling it is evaporated under anhydride and the whole is stirred in for 48 hours in a dry 45 repeated addition of toluene and crystallized in a nitrogen atmosphere. The reaction, which has become cloudy, is freed of toluene by evaporation with ether, the mixture is then converted to a solid residue from acetone in vacuo at 20 to 25 °. The whole is vaporized, with toluene being added as an entrainer to remove the excess 4.20 mg of pure d, l-21-0-acctyl-aldosterone in colorless acetic anhydride. obtained fine prisms with a melting point of 178 to 180 °. ^{100 cm 3 of} 50 are poured over the semi-solid residue. After renewed treatment with 1 M potassium sodium tartrate solution and 100 cm ^{3 of} methylene-boiling 90 ° acetic acid, evaporation and anhydrous chloride, the closed flask is shaken for 30 minutes by preparative paper chromatography. The aqueous phase is then separated off in the formamide cyclohexane - benzene - system and it is extracted twice with 50 cm ^{3 of} methylene (1: 2) each time in the manner indicated below under b) chloride. With 1 m 55, the organic solutions become a further 1.63 mg with a melting point of 177 ° to 178 °. Potassium sodium tartrate solution and washed with water, b) From pure 21-O-monoacetyl diketal: a solution combined, dried with sodium sulfate and evaporated. of 2.497 g of the monoacetate described in Example 2. The colorless residue crystallizes from ether. It is in 118 cm ³ 90 ° / ₀ acetic acid is dissolved in nitrogen in 10 cm ³ of benzene and 12.1 g of silica gel atmosphere boiled in an oil bath for 15 minutes. After cooling (known under the trade name "Davison, THRU200") 60, the acetic acid is evaporated on the oil pump and chromatographed using the continuous flow method. For complete elution with the addition of a total of 75 cm 'of toluene, 40 cm ^{3 of} the solvent is used per fraction and the retained toluene is finally displaced by the following solvent: by evaporation with ether. From the crystalline

Residue can be obtained by recrystallizing twice

Fraction 1 + 2 benzene 65 sieren from acetone as a peak fraction 797 mg pure

Fraction 3 + 4 benzene-ether (99: 1) d.l ^ l-O-acetyl-aldostcron in colorless, fine prisms

Fraction 5 + 6 benzene-ether (95: 5) obtained from melting point 178 to 180 °. The evaporation

Fraction 7 + 8 benzene-ether (75:25) residue of the first mother liquor (991 mg) is again

Fraction 9 + 10 benzene-ether (50:50) for 15 minutes with boiling 90 ° / _o acetic acid

Fraction 11 + 12 ether 70 treated, then the solution as described above

Claims (4)

gedaiiij> ft and the residue dissolved in 38.5 cm3 of methylene chloride on 350 sheets of formamide-soaked Whatman paper No. 1 (18.5 x 45 cm) chromatographed for 24 hours in the formamide / cyclohexane-benzene (1: 2) system After drying the leaves in air for 24 hours, the strongly UV-absorbing zone with an Rf value of 0.16 is cut out, the paper is first dried for a further 16 hours at 40 ° in a high vacuum and then eluted with a total of 1600 cm3 of 20% aqueous tetrahydrofuran The collected extract is evaporated under reduced pressure to a residual volume of about 200 cm3 and the aqueous concentrate is shaken out several times with methylene chloride. After washing, the extracts are combined with water, dried with sodium sulfate and evaporated. The yellow-tinged eluate, which crystallizes completely from ether, weighs dry 321 mg. The evaporation residue of the second mother liquor (259 mg) is separated by paper chromatography in the same way and yields 127 mg of eluate Purification, both fractions are dissolved together in 45 cm3 of tetrahydrofuran and the solution is filtered through a column of 1.125 g of activated charcoal. The filtrate leaves a colorless residue on evaporation, from which a total of 345 mg of pure 21-monoacetate with a melting point of 178 ° to 180 ° can be obtained by recrystallization from acetone. The crystals obtained from acetone give a C value that is too low in the combustion analysis, which is due to a content of hard-to-remove crystal solvent that can be detected by IR spectroscopy. The substance also crystallizes from boiling benzene with solvent, but this is completely given off in a vacuum at 125 to 130 ° in the course of 12/2 hours. The racemic 21-O-acetyl-aldosterone also exists in a solvent-free modification which melts at 204 to 206 ° and which forms particularly easily when the benzene-containing crystals described above are slowly heated. . In an analogous manner, d- or 1-21-O-acetyl-aldosterone is obtained from the 18,21-di-O-acetyl-diketals of d- or 1-aldosterone. EXAMPLE 4 A solution of 40.25 mg of d, l-21-0-acetyl-aldosterone in 1.25 cm3 of methylene chloride is admixed all at once with 2.5 cm3 of 0.05 m potassium carbonate in 75% methanol, while swirling around. After an exposure time of 4 minutes, the excess alkali is blunted by throwing in a piece of dry ice and then using the water jet pump to concentrate the reaction solution to a final volume of about 0.75 cm3. During the concentration, after removing the methylene chloride, a further 1.0 cm3 of water is added. The resulting crystal suspension is suction filtered while rinsing with a total of 3.0 cm3 of ice-cold water and the crystals are dried in vacuo over calcium chloride. This gives 31.15 mg of practically pure d, l-aldostcron in fused platelets with a melting point of 178 ° to 180 °. As the papierchxOmatographic analysis in the system propylene glycol - toluene shows, the preparation still contains a small amount (about 3%) of a somewhat slower moving, UV-absorbing impurity, which also reduces blue tetrazolium. For separation, the material is dissolved in 1.60 cm3 of methylene chloride and, after application to 16 sheets of propylene glycol-soaked Whatman paper No. 1 (format 18.5 x 45 cm; washed with chloroform and methanol), is chromatographed for 20 hours in the propylene glycol - toluene system. The main band is cut out and eluted with 20% aqueous tetrahydrofuran. When recrystallized from methanol-water, the extract, further worked up in the usual way, gives 15.7 mg of pure d, l-aldosterone in colorless, fused platelets which, when slowly heated above 120 °, transform into coarse crystals, which finally at 197 to Melting 204 °. Example 5 A finely crystalline suspension of 402.5 mg of d, l-21-O-acetyl-aldosterone in 125 cm3 of a 0.1 η solution of potassium hydrogen carbonate in 80% aqueous methanol is in a nitrogen atmosphere at 20 to 23 ° Shaken until the starting material has completely dissolved and the resulting solution is then left to stand for 3 hours at the same temperature until work-up the mixture in vacuo at a bath temperature of 30 to 35 ° to a residual volume of about 10 cm3. After standing for 15 minutes, the resulting crystals are separated from the mother liquor by suction, washed with a total of 25 cm3 of ice-cold water and dried at room temperature 323.4 mg of practically pure d, l-aldosterone in small, colorless glands with a temperature of 179 to 181 °. PAT K NT Λ Ν SP KITCHEN: 1. A process for the preparation of aldosterone and its derivatives, characterized in that in a (18 - * ■ ll) -lactone a <d ^s -3,20-bis-alkylenedioxy-ll ^, 21-dihydroxy-pregnen-18 acid or its 21-esters, the lactone group is reduced with lithium aluminum hydride to (18 - »- IIJ-cyclohemiacetal, the product obtained is treated with an acylating agent and, optionally after hydrolysis of the 18 acyloxy group, the protected oxo groups in the 3- and 20-positions acid hydrolysis sets free and optionally saponifies the 21-acyloxy group under alkaline conditions. 2. The method according to claim I _1, characterized in that the metal salt formed in the lithium aluminum hydride reduction is treated directly with an acylating agent. 3. The method according to claim 1, characterized in that the ketal cleavage is carried out by heating carried out with an aliphatic carboxylic acid in an aqueous medium. 4. The method according to claim 1, characterized in that one for the saponification of an aldosterone-21-monoacylate an alkali metal carbonate or bicarbonal: used. 8- 909 640/427 10.