Patent number: 6492522
Abstract: The present invention relates to a new process for the preparation of acetylcholinesterase inhibitors of formula (I) or a salt thereof, wherein: R1 is N-acyl-4-piperidyl; N-alkoxycarbonyl-4-piperidyl; N-alkyl-4-piperidyl; N-benzyl-4-piperidyl; N-(&ohgr;-aralkyl)-4-piperidyl; 4-pyridyl; R4, R5, R6, and R7 are identical or different and each represents hydrogen, straight-chain or branched alkyl, aryl, hydroxy, alkoxy, aryloxy, benzyloxy, acyloxy, alkylthio, arylthio, benzylthio, acylamino, phthalimido or halogen; n is 1, 2 or 3; m is 1, 2, 3, 4, or 5. This process comprises cyclisation of a compound of formula (II) or salts thereof, wherein R1, R4, R5, R6 and R7, m and n are as defined above; R2 is selected from a derivatised or non-derivatised carboxyl, cyano, N-substituted aminocarbonyl groups or hydrogen; R3 is selected from a derivatised or non-derivatised carboxyl, cyano or N-substituted aminocarbonyl groups, optionally in the presence of acids and/or solvents.
Type:
Grant
Filed:
May 24, 2001
Date of Patent:
December 10, 2002
Assignee:
Finetech Laboratories Ltd.
Inventors:
Arie L. Gutman, Eleonora Shkolnik, Boris Tishin, Genady Nisnevich, Igor Zaltzman