METHOD FOR OBTAINING CONTRACEPTIVE PREPARATION FOR ANIMALS Russian patent published in 2006 - IPC A61K31/57 C07J5/00 A61P15/00 

FIELD: veterinary pharmacology.

SUBSTANCE: The suggested method deals with interaction of valerianic acid anhydride with steroid alcohol - 17α-acetoxy-3β-hydroxy-6-methylpregna-4.6-dien-20-on at molar ratio being 1.1-1.5:1 to steroid, which should be implemented in pyridine medium in volume-weight ratio of 1.5-2.0:1 pyridine to steroid at 22-25°C, excess of anhydride should be hydrolyzed with water at the quantity of 15-20% against the volume of reaction mass, as for developed valerianic acid, it should be dissolved in 1-1.5%-ammonia aqueous solution and a target product should be filtered, washed with water up to neutral reaction to be washed with methanol. The innovation provides obtaining new target product of higher purification degree.

EFFECT: higher efficiency.

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