PIPERAZINE DERIVATIVES AND THEIR PHARMACEUTICALLY ACCEPTABLE ESTERS AND ACID-ADDITIVE SALTS Russian patent published in 1997 - IPC

FIELD: organic chemistry. SUBSTANCE: product: derivatives of piperazine of the general formula (I): or their pharmaceutically acceptable esters, or their acid-additive salts where: R¹ - hydrogen, lower alkyl or lower alkoxy; R² - hydrogen, lower alkoxy, halide, trifluoromethyl or alkylthio; R³ - hydrogen, lower alkyl, lower alkoxy, halide or cyano-group; R⁴ - hydrogen or lower alkoxy; R⁵ - hydrogen or lower alkyl; R⁶ - hydrogen, lower alkyl, lower acyl, lower alkoxy; R⁷ - hydrogen, lower alkoxy, trifluoromethyl, halide or together with R⁶ forms the group: -CH=CH-CH=CH-; R⁸ - hydrogen, lower alkyl, lower alkoxy, halide, aminocarbonylmethyl, cyano or di(lower)alkylamino; R⁹ and R¹⁰ each independently - hydrogen or lower alkoxy; R¹¹ and R¹² - each independently - hydrogen or lower alkyl; W - oxygen. Reagent 1: the corresponding derivative of piperidine. Reagent 2: alkylating agent containing one of by-side chains. Reaction conditions: inert solvent, at 60-150 C for 6-24 h. Synthesized compounds were used in medicine for treatment of cardiovascular system diseases. EFFECT: improved method of synthesis. 1 tbl