NO126318B - - Google Patents

Description

Analogy method in the production of

therapeutically active 1incomycin derivatives.

The present invention relates to an analogue method for the production of new, therapeutically active lincoraycin derivatives, which are 7-halogen-7-deoxylincomycins and 7-halogen-7-deoxyepilincomycins, and analogues and isomers thereof.

The new compounds produced according to the invention have the general formula:

where X is chlorine or bromine, R is methyl or ethyl, R, is alkyl with 2-8 carbon atoms, and R^ is hydrogen, methyl or ethyl, and acid addition salts thereof.

The new compounds of formula I are prepared according to the invention by a compound of the formula: where R and X are as indicated above, N-acylated in a known manner for N-acylation of amino sugars, the acyl group of an acid of the formula:

where R-^ is as above, and R^ is R^ or Z, where Z is one

protective hydrocarbyloxycarbonyl group which can be removed by hydrogenolysis, trityl, diphenyl-(p-methoxyphenyl)-methyl, bis-(p-methoxy-phenyl)-phenylmethyl, benzyl or p-nitrobenzyl, is introduced after which R 2 when this is Z, is replaced by hydrogen - in a manner known per se, and the compound obtained, if desired, is transferred to an acid addition salt thereof in a manner known per se.

The starting compounds of formula II are prepared by replacing the 7-hydroxy group in a compound of the formula:

where R is as indicated above, with chlorine or bromine.

The recovery is advantageously carried out by heating a compound of formula IV with a Rydon reagent, as described in Norwegian specification no. 123.6O9.

The starting acid of formula III can be prepared by reacting a 4-oxo compound of the formula:

where Z is a protecting hydrocarbyloxycarbonyl group which can be removed by hydrogenolysis, trityl, i.e. triphenylmethyl, diphenyl-(p-methoxyphenyl)-methyl, bis-(p-methoxyphenyl)-phenylmethyl, benzyl or p-nitrobenzyl with a Wittig reagent, f .ex. an alkylidenetriphenylphosphorane [see e.g. Wittig et al., Ber., 8_7_, 1348 (1954); Trippett, Quarterly Reviews, XVII, No. 4, pp. 4o6 (1963)]. Examples of hydrocarbyloxycarbonyl groups (Z) are tertiary-butoxy-carbonyl, benzyloxycarbonyl groups of the formula: where X is hydrogen, nitro, methoxy, chlorine or bromine, e.g. carbo-benzoxy, p-nitrocarbobenzoxy, p-bromo- and p-chlorocarbobenzoxy, and phenyloxycarbonyl groups of the formula: where X-^ is hydrogen, allyl or alkyl of not more than h carbon atoms, such as phenyloxycarbonyl, p-tolyloxycarbonyl, p-ethylphenyloxy- carbonyl and p-allylphenyloxycarbonyl and the like. When carrying out this method, the <1>+-oxo-L-2-pyrrolidine carbonyl acid (formula V) is added to a freshly prepared Wittig reagent. The Wittig reagent used here can generally be expressed by the following formula: \where R<1>^ is oxygen, the alkylidene with 2-8 carbon atoms. These Wittig reagents are prepared by reacting an alkyltriphenylphosphonium halide with a base such as sodium amide or sodium or potassium hydride, or the sodium or potassium metalate of dimethylsulfoxide and the like. For example, the elimination of hydrogen halide from alkyltriphenylphosphonium halide produces alkylidenetriphenylphosphorane. [The preparation of phosphoranes is described in detail by Trippett, Quart. Fox. XVII. No. !+, pp. ^06 (1963)]. The reaction is generally carried out in an organic solvent such as benzene, toluene, ether, dimethylsulfoxide, tetrahydrofuran or the like, at temperatures between 10°C and the reflux temperature of the reaction mixture. The product thus obtained, a ^-alkylidene-protected-L-proline having the formula: is recovered from the reaction mixture in a conventional manner, generally by extraction from aqueous solutions of the reaction mixture. The crude product can be purified in a conventional manner, such as by recrystallization, chromatography or formation and recrystallization of easily formed derivatives, such as amine salts of the amino acid, e.g. the dicyclohexylamine salt,• and the like, and liberation of the amino acids from such compounds. When hydrogenating an acid of the formula IX in the presence of a catalyst, e.g. platinum, which is effective in saturating a double bond, but is ineffective in producing hydrogenolysis, a compound of the formula is obtained:

Platinum deposited on a support, e.g. carbon or an anion exchange resin such as "Dowex-1", a cross-linked polystyrene-trimethyl-benzammonium resin in the hydroxyl form is suitable.

The compounds of formula I where R^ is hydrogen are obtained when a compound of formula I where R^ is Z is subjected to hydrogenolysis over a palladium catalyst, e.g. palladium on carbon.

The starting compounds of formula II can be prepared by hydra*zinolysis of a compound of the formula:

where R is as above, and Ac is an acyl group.

The hydrazinolysis can be carried out as described in U.S. Pat. patent

3,179,565.

Option I

Preparation of the starting compounds of formula X is described in more detail in generally available Norwegian application No. 161.594.

Option II

Some of the starting compounds of formula X are obtained bisynthetically.

Lincomycin, methyl-6,8-dideoxy-6-(trans-1-methyl-4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-D-erythro-α-D-galacto-octopyranoside, is obtained as a work-up product of a lincomycin-producing actinomycete according to U.S. Pat. patent No. 3,086,912. It has the following structural formula:

where R and R^ are methyl and RJ is propyl. Lincomycin B, methyl-6,8-dideoxy-6-(trans-1-methy1-4-ethyl-L-2-pyrrolidinecarboxamido)-1-thio-D-erythro-α-D-galacto-octo-pyranoside (formula XI where R and R^ are methyl, and R^ is ethyl) is also a work-up product of the same microorganism when grown according to the method of

U.S. patent No. 3,086,912. Lincomycin C, S-ethyl-S-demethyl-lincomycin, ethyl-6,8-dideoxy-6-(trans-1-methyl-4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-D-erythro-α-D -galacto-octopyranoside (formula XI where R is ethyl, R| is propyl, and R^ is methyl) is obtained when the method in the U.S. patent no. 3,086,912 is carried out in the presence of added ethionine. Lincomycin D, methyl-6,8-dideoxy-6-(trans-4-propyl-L-2-pyrrolidinecarboxami'do)-1-thio-D-erythro-α-D-galactooctopyrano-side (formula XI where R is methyl, R^ is propyl and R^ is hydrogen) is obtained when the fermentation in the U.S. patent No. 3,086,912 is carried out in the presence of added α-MTL, methyl-6-amino-6,8-dideoxy-D-erythro-1-thio-α-D-galactooctopyranoside, a compound obtained by hydrazinolysis of lincomycin according to U.S. Patent No. 3,179,595, N-demethyl-lincomycin B. Methyl-6,8-dideoxy-6-(trans-4-ethyl-L-2-pyrrolidine-carboxamido)-1-thio-D-erythro-α-D- galacto-octopyranoside (formula XI where R is methyl, R| is ethyl and R^ is hydrogen) is also formed when α-MTL is added to the fermentation in the U.S. patent No. 3-086,912. In a similar manner, lincomycin.K, ethyl-6,8-dideoxy-6-(trans-4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-D-erythro-α-D-galacto-octopyranoside (formula XI where R is ethyl, R£ is propyl and R^ is hydrogen) when the fermentation according to the U.S. patent no. 3-086,912 is carried out in the presence of added α-ETL, ethyl-6-amino-6,8-dideoxy-D-erythro-α-thio-D-galacto-octopyranoside, a compound obtained by hydrazinolysis of lincomycin C (S-ethyl-S,N-didemethyllincomycin, B). Ethyl-6,8-dideoxy-6-(trans-4-ethyl-L-2-pyrrolidine-carboxamido)-1-thio-D-erythro-α-D-galacto-octopyranoside (formula XI where R is ethyl, R£ is ethyl and R^ is hydrogen) is also obtained when α-ETL is added during the fermentation in the U.S. patent No. 3-086,912.

Lincomycin or any of the parent compounds of formula X having the D-erythro configuration can be transferred to the L-threo configuration by oxidizing the 7-hydroxy group to a J-oxo group and then reducing the latter to a 7-hydroxy group. A suitable procedure for this purpose is illustrated by the following sequence:

For example, lincomycin is transferred by treatment with acetone in the presence of p-toluenesulfonic acid to 3,^-O-isopropylidene lincomycin which, on oxidation with chromium oxide, gives 7-dehydro-3,V-0-isopropylidene lincomycin, (methyl-é^-dideoxy-M-, 5-0-isopropylidene-6-( trans-1-methyl-^-propyl-L-2-pyrrolidinecarboxamido)-1-thio-D-glycero-oc-D-galacto-octanepyranos-7-uloside) as when treated with sodium borohydride is transferred to 7-epilincomycin, (methyl-6,7-dideoxy-6-(trans-1-methyl-H-propyl-L-2-pyrrolidinecarboxamido)-1-thio-L-threo-α-D-galacto-octopyranoside. Any of the starting compounds of formula x with a D-erythro configuration can be converted to the corresponding L-threo configuration by this method.

The compounds of formula I exist either in the proton-

protonated or non-protonated form depending on the pH of the environment. When the protonated form is meant, the compound is referred to as an acid addition salt, and when the non-protonated form is meant, it is referred to as the free base. The free bases can be converted to stable acid addition salts by neutralizing the free base with a suitable acid to less than approx. pH 7.0, and preferably to approx. pH 2 to pH 6. Suitable acids for this purpose include hydrochloric acid, sulfuric acid, phosphoric acid, thiocyanic acid, fluorosilicic acid, hexafluoroarsenic acid, hexafluorophosphoric acid, acetic acid, succinic acid, citric acid, lactic acid, maleic acid, fumaric acid, pamoic acid (pamoic acid), cholic acid, palmitic acid, mucic acid, camphoric acid, glutaric acid, glycolic acid, phthalic acid, tartaric acid, lauric acid, stearic acid, salicylic acid, 3-phenyl-salicylic acid, 5-phenylsalicylic acid, 3-methylglutaric acid, orthosulfobenzoic acid, cyclopentanepropionic acid, 1,2-cyclohexane-dicarboxylic acid, ^--cyclohexanecarboxylic acid . , benzoic acid, cinnamic acid and similar acids.

The acid addition salts can be used for the same purposes as the free base, or they can be used to purify this. For example, the free base can be transferred to an insoluble salt, such as picrate, which can be subjected to purification processes, e.g. solvent extractions and washings, chromatography, fractional liquid-liquid extractions, and crystallization, and then used to regenerate the free acid form by treatment with alkali or to prepare another salt by metathesis. Or the free base may be converted to a water-soluble salt, such as the hydrochloride or sulfate, and the aqueous solution of the salt may be extracted with various water-immiscible solvents for regeneration of the free base form by treatment of the acid solution thus extracted^ or transferred to a other salt by metathesis.

The closest analogues of lincomycin, i.e. where -R^ is cis- or trans-alkyl with no more than 8 carbon atoms, R^ is methyl or ethyl, and R is methyl or ethyl, have antibacterial properties and some are comparable or superior to lincomycin and can be used for the same purpose as lincomycin. ■ The corresponding compounds where R 1 is hydrogen have similar antibacterial properties, and also have improved Gram-negative activity. The activity of the process compounds is discussed in more detail in the Journal of Medicinal Chemistry 12, ?80 - 7% h and 1}, 616 - 619.

The following example illustrates the present method and the method products. Percentages are given by weight.

Example

Methyl-7(S)-chloro-6J7,8-trideoxy-6-(lf-trans- and cis-propyl-L-2-pyrrolidinecarboxamido)- 1- thio- q- D- galacto- octopyranoside Acylation

2.33 g of cis- and trans-1-carbobenzoxy-β-propyl-L-proline were dissolved in 150 ml of acetonitrile containing 1.12 ml of triethylamine.

The solution was cooled to 0°C and 1.18 ml of isobutyl chloroformate was added. After 10 minutes at 0°C, a solution of 2.17 g of methyl-7(S)-chloro-7-deoxy-α-thiolincosaminide in 40 ml of acetonitrile and 40 ml of water was added. The mixture was stirred for 2 hours at ambient temperature and the solvent was distilled off in vacuo, whereby a crystalline residue was obtained.

The crystals were collected by filtration, washed and dried. Yield of methyl-N-(1-carbobenzoxy-4-trans- and cis-propyl-L-prolyl)-7(S)-chloro-7-deoxylincosaminide, m.p. 180-183°C, was 3.36 g. Endel was recrystallized several times from ethanol and then melted

at 189-192°C.

Analysis - Calculate, for Z2^^ Q. Vi\ £>^ S:

C 55.08; H 6.84; Cl 6.51; N 5.14;

Found: C 54.80; H 7.15; Cl 6.59; N 5.16%.

When in the above acylation instead of the mixed anhydride prepared from cis- and trans-1-carbobenzoxy-4-propyl-L-proline and isobutyl chloroformate, cis- and trans-l-carbobenz-oxy-4-propyl-L-proline anhydride is used or cis- and trans-1-carbobenzoxy-4-propyl-L-2-pyrrolidinecarboxylic acid chloride, the same product is obtained.

Hydrogenolysis

A portion of the crude product from the above step was dissolved in 50 ml of methanol, and 0.5 g of 10% palladium-on-charcoal was added. The mixture was shaken under a hydrogen pressure of 2.46 kg/cm 2 for 4 hours. Thin layer chromatography showed partial hydrogenolysis. An additional 0.5 g of catalyst was added and the hydrogenation continued for 18 hours. The catalyst was removed by filtration. The residue was chromatographed over silica gel, and the more polar fraction collected. It weighed 185 mg. It was transferred to the hydrochloride in the usual manner, yielding 150 mg of crystals, m.p. 220 - 222°C during cleavage, with an activity approximately four times that of lincomycin.

Another portion of the crude product (22.9 g) was dissolved in 500 ml of methanol, and 6.0 g of 10% palladium-on-charcoal was added. The mixture was shaken under a hydrogen pressure of 2.46 kg/cm for 18 hours. The catalyst was removed by filtration, and the clear liquid phase was evaporated. The solid crude product was transferred to the hydrochloride. Crystallization of the crude product from acetone-water gave 15.08 g of crystals of methyl-7(S)-chloro-6,7,8-trideoxy-6-(4-trans - and cis-propyl-L-2-pyrrolidinecarboxamido) -1-thio-l-threo-α-D-galacto-octo-

pyranoside hydrochloride with m.p. 218 - 223°C (decomposition). About-

crystallization from water gave an analytical sample with m.p. 228 - 234°C

(decomposition), [a]Q + 159°.

Calculated, for C1^H22Cl2N2Ot-S:

C 45.63; H 7.21; N 6.26.

Found: (corrected for 3.91% H 2 O) C 45.85; H 7.51; N 5.86%.

Other methods for the acylation of amino sugars are set forth in: "The

Monosaccharides" by Jaroslav Stanek et al. (1963), page 509, publ

of the Publishing House of the Czechoslovak Academy of Sciences,

Prague.

Claims (1)

Analogous procedure for the preparation of therapeutically active lincomycin derivatives of the formula: where X is chlorine or bromine, R is methyl or ethyl, is alkyl with 2-8 carbon atoms, and R^ is hydrogen, methyl or ethyl, and acid addition salts thereof, characterized by a compound of the formula: where R and X are as indicated above, is N-acylated on for N-acylation of amino sugars in a known manner, the acyl group of an acid of the formula: where is as above, and R 2 is R 2 or Z, where Z is a protecting hydrocarbyloxycarbonyl group which can be removed by hydrogenolysis, trityl, diphenyl-(p-methoxyphenyl)-methyl, bis-(p-methoxyphenyl)-phenylmethyl, benzyl or p-nitrobenzyl, is introduced, after which R ? when this is Z, is replaced by hydrogen in a manner known per se, and the compound obtained, if desired, is converted to an acid addition salt thereof in a manner known per se.