Process for the preparation of spiro[(4-cyclohexanone)-[3]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 the general formula Iwherein Rand Rindependently stand for hydrogen, Calkyl, Calkoxy, Calkylthio, Cpolyfluoroalkyl, Cpolyfluoroalkoxy, Ccycloalkyloxy, Ccycloalkylthio, phenoxy, benzyloxy or nitro group—,characterized by reacting an indolin-2-one derivative of the general formula IIwherein Rand Rare as defined above—with a compound capable for introducing a protective group, selected from 2-tetrahydropyranyl, 1-diethoxy-methylene or Calkoxycarbonylethyl group, coupling the compound of general formula III,thus obtained—wherein Rand Rare as defined above and A stands for a protective group, selected from 2-tetrahydropyranyl, 1-diethoxy-methylene or Calkoxycarbonylethyl group—with an acrylic acid Cester, cyclizing the resulting compound of the general formula IVwherein R, Rand A are as defined above, Rstands for Calkyl group—, eliminating the —COORgroup and the A protective group of the keto-ester of general formula Vwherein R, R, Rand A are as defined above, optionally without isolation of the compounds of the general formulae IV