Process for the preparation of spiro[(4-cyclohexanone)-[3h]indol]-2′[1′h]-one derivatives

Abstract

The invention relates to a process for the preparation of spiro [(4-cyclohexanone)-[3H]indol]-2′[1′H]-one derivatives of general formula I—wherein R and R independently stand for hydrogen, C alkyl, C alkoxy, C alkylthio, C polyfluoroalkyl, C polyfluoroalkoxy, C cycloalkyloxy, C cycloalkylthio, phenoxy, benzyloxy or nitro group—, characterized by reacting an indolin-2-one derivative of general formula II—wherein R and R are as defined above—with a compound capable for introducing a protective group, coupling the compound of general formula III, thus obtained—wherein R and R are as defined above and A stands for a protective group—with acrylic acid C ester; cyclizing the resulting compound of general formula IV—wherein R and R are as defined above—with a compound capable for introducing a protective group, coupling the compound of formula III thus obtained,—wherein R and R are as defined above and A stands for a protective group—with an acrylic acid C ester, cyclizing the resulting compound of formula IV—wherein R and R are as defined above R stands for C alkyl and A stands for a protective group—, eliminating the—COOR group and the A protective group of the keto-ester of general formula V—wherein R and R are as defined above, R stands for C alkyl and A stands for a protective group—, optionally without isolation of the compounds of general formulae IV and/or V and/or VI.