摘要 |
The invention relates to a process for the preparation of spiro[(4-cyclohexanone)-[3H]indol]-2'[1'H]-one derivatives of the general formula I wherein R<SUP>1 </SUP>and R<SUP>2 </SUP>independently stand for hydrogen, C<SUB>1-4</SUB>alkyl, C<SUB>1-4</SUB>alkoxy, C<SUB>1-4</SUB>alkylthio, C<SUB>1-4</SUB>polyfluoroalkyl, C<SUB>1-4</SUB>polyfluoroalkoxy, C<SUB>3-7</SUB>cycloalkyloxy, C<SUB>3-7</SUB>cycloalkylthio, phenoxy, benzyloxy or nitro group-, characterized by reacting an indolin-2-one derivative of the general formula II wherein R<SUP>1 </SUP>and R<SUP>2 </SUP>are as defined above-with a compound capable for introducing a protective group, selected from 2-tetrahydropyranyl, 1-diethoxy-methylene or C<SUB>1-4</SUB>alkoxycarbonylethyl group, coupling the compound of general formula III, thus obtained-wherein R<SUP>1 </SUP>and R<SUP>2 </SUP>are as defined above and A stands for a protective group, selected from 2-tetrahydropyranyl, 1-diethoxy-methylene or C<SUB>1-4</SUB>alkoxycarbonylethyl group-with an acrylic acid C<SUB>1-4</SUB>ester, cyclizing the resulting compound of the general formula IV wherein R<SUP>1</SUP>, R<SUP>2 </SUP>and A are as defined above, R<SUP>3 </SUP>stands for C<SUB>1-4 </SUB>alkyl group-, eliminating the -COOR<SUP>3 </SUP>group and the A protective group of the keto-ester of general formula V wherein R<SUP>1</SUP>, R<SUP>2</SUP>, R<SUP>3 </SUP>and A are as defined above, optionally without isolation of the compounds of the general formulae IV
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