METHOD OF SYNTHESIS OF PHYSOSTIGMINE DERIVATIVES (VARIANTS) Russian patent published in 1998 - IPC

FIELD: organic chemistry and technology. SUBSTANCE: invention relates to new methods of synthesis of compound of the general formula (I) where R - lower alkyl; R¹ - hydrogen atom; R² - lower alkyl, lower cycloalkyl; lower cycloalkyl-lower alkyl, lower bicycloalkyl, aryl or aryl-lower alkyl, or R¹ and R² form with nitrogen atom to which they are bound the group 3,4-dihydro-2(1H)-isoquinoline; X - lower alkyl, lower alkoxy, halogen atom or trifluoromethyl group; m = 0, 1 or 2. Synthesis is carried out by interaction of compound of the general formula (II) where R, X and m have values indicated above and R³ - lower alkyl with alkyl-lithium or alkaline metal alcoholate followed by interaction with carboxylic acid of the general formula R⁵-COOH where R⁵ - lower alkyl and compound of the general formula (III) where R, X and m have values indicated above is obtained. Then synthesis involves interaction of reaction mass containing compound of the general formula (III) with isocyanate of the general formula R²-NCO and compound of the general formula (I) where R¹ - hydrogen atom is obtained, or compound of the general formula (IV) where R⁴ - hydrogen atom or lower alkyl in the presence of carboxylic acid of the general formula R⁵-COOH where R⁵ has value indicated above and compound of the general formula (V) where R, R⁴, X and m have values indicated above is obtained by contact of reaction mixture containing the compound of the general formula (V) with compound of the general formula R¹R²-NH where R¹ and R² have values indicated above and isolation of compound of the general formula (I). EFFECT: improved method of synthesis. 19 cl, 1 tbl