Patent ID: 6573386
Filing Date: 2003-06-03
Classification: C07D,Y02P

Abstract:
A process for the preparation of spiro[(4-cyclohexanone)-[3H]indol]-2â€²[1â€²H]-one derivatives of the general formula I â€”wherein R1 and R2 independently stand for hydrogen, C1-4alkyl, C1-4alkoxy, C1-4alkylthio, C1-4polyfluoroalkyl, C1-4polyfluoroalkoxy, C3-7cycloalkyloxy, C3-7cycloalkylthio, phenoxy, benzyloxy or nitro group which comprises reacting an indolin-2-one derivative of the general formula II â€”wherein R1 and R2 are as defined aboveâ€”with a compound selected from 2,3-dihydropyrane, triethylorthoformate or acrylic acid C1-4ester capable for introducing a protective group, selected from 2-tetrahydropyranyl, 1-diethoxy-methylene or C1-4alkoxycarbonylethyl group to produce a compound of general formula III, coupling the compound of general formula III, thus obtainedâ€”wherein R1 and R2 are as defined above and A stands for a protective group, selected from 2-tetrahydropyranyl, 1-diethoxy-methylene or C1-4alkoxycarbonylethyl groupâ€”with an acrylic acid C1-4ester to produce a compound of formula IV, cyclizing the resulting compound of the general formula IV â€”wherein R1, R2 and A are as defined above, R3 stands for C1-4alkyl groupâ€”, to produce a compound of general formula V and eliminating theâ€”COOR3 group and the A protective group of the keto-ester of general formula V to produce a compound of general formula I wherein R1, R2, R3 and A are as defined above, optionally without isolation of the compounds of the general formulae IV