CONTRACEPTIVE AGENT FOR ANIMAL AND A METHOD OF ITS SYNTHESIS Russian patent published in 1997 - IPC

FIELD: organic chemistry, steroids. SUBSTANCE: agent has the preliminary micronized progestagen - 3,17-dihydroxy-6-methylpregna-4,6-diene-20-one or its esters of the formula (I): where: R and R′ - H or acyl-group containing 1-6 carbon atoms being R can be similar with R′ or different of its. Agent can contain additionally the preliminary micronized natural or synthetic estrogen. Method of synthesis involves acylation reaction using minimal amount of acylating agent: 1.1-1.5 mole per 1 mole steroid. Reaction is carried out for a single stage without use of pyridine and additional purification. Acylation reaction is carried out in medium consisting of 3-5 volumes of dialkylketone per 1 weight part of steroid. The used catalyst is tertiary amine, for example, triethanolamine or 2,4,6-tris-(dimethylaminomethyl)-phenol or 4-(dimethylamino)-pyridine or their combination. EFFECT: improved method of synthesis, simplified method, decreased reagent consumption. 4 cl