METHOD OF OBTAINING (±)N-[1-(4-FLUOROPHENYL)-2-(1-ETHYLPIPERIDIN-4-YL)ETHYL]-4-NITROBENZAMIDE OR ITS PHARMACEUTICALLY ACCEPTABLE SALTS AND INTERMEDIATE COMPOUND FOR OBTAINING THEREOF Russian patent published in 2015 - IPC C07D211/28 C07D211/32 

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention relates to novel method for obtaining (±)N-[1-(4-fluorophenyl)-2-(1-ethylpiperidin-4-yl)ethyl]-4-nitrobenzamide, corresponding to structural formula (I) or its pharmaceutically acceptable salts. Method mainly relates to hydrochloride of formula (I) compound (niferidil hydrochloride). Niferidil hydrochloride is used as medication for treatment of atrial fibrillation in people. In accordance with claimed method formula (I) compound is obtained by interaction of ethyl ether of 4-fluorobenzoic acid with 4-picoline in tetrahydrofurane in presence of catalyst or condensing means with obtaining 1-(4-fluorophenyl)-2-(4-pyridyl)ethanol. It is preferable to use sodium bis(trimethylsilyl)amide as condensing agent in amount 1-2 moles per a mole of 4-fluorobenzoate. Obtained compound is alkylated with ethylhalogenide with obtaining respective pyridinium salt. The latter is subjected to catalytic reduction with hydrogen in presence of palladium or platinum catalyst with addition of concentrated hydrochloric acid for obtaining 2-(1-ethylpiperidin-4-yl)-1-(4-fluorophenyl)ethanol of formula (II) which is subjected to reductive amination with obtaining [2-(1-ethylpiperidin-4-yl)-1-(4-fluorophenyl)-ethyl]amine, with further interaction of the latter with acid chloride of 4-nitrobenzoic acid with obtaining (±)N-[1-(4-fluorophenyl)-2-(1-ethylpiperidin-4-yl)ethyl]-4-nitrobenzamide of formula (I) in free form or in form of its pharmaceutically acceptable salt. Formula (II) compound is a novel intermediate compound.

EFFECT: method makes it possible to simplify and cheapen the process due to reduction of number of stages, as well as to improve quantity of obtained target product to 99,6% by HPLC data.

5 cl, 1 ex