SYNTHESIS OF SUBSTITUTED t-BUTYL 3-ALKYLOXINDOLE-3-CARBOXYLATES FROM DI-t-BUTYL (2-NITROPHENYL)MALONATES

摘要

Using a novel tandem reduction-cyclization, we synthesized t-butyl 3-alkyloxindole-3-carboxylates from the di-t-butyl 2-alkyl-2-(2-nitrophenyl)malonate. Introduction of an alpha-substituent to the di-t-butyl 2-(2-nitrophenyl)-malonates and addition of acid promoted reactivity. This methodology was successfully applied to gram-scale-synthesis of the t-butyl 3-methyloxindole-3-carboxylate 1 and 3-hydroxyrnethy1-3-methyloxindole 2 without silica gel column chromatography.