Synthesis of substituted azaoxindoles for the preparation of aza‐tenidap analogs

Abstract

Abstract The preparation of a set of eight azaoxindoles bearing substituents on the aromatic nucleus is outlined. These compounds were required for the preparation of aza‐analogs of the anti‐inflammatory oxindole tenidap. Two methods of synthesis were used, the first involving the addition of malonate to 2‐chloro‐3‐nitropyridine derivatives followed by nitro group reduction and one‐pot cyclization/hydrolysis/decarboxylation. The second method, utilizing the vicarious nucleophilic substitution (VNS) reaction of nitropyridine derivatives (followed by nitro group reduction and one‐pot cyclization/hydrolysis), constitutes a novel route to azaoxindoles.