Tetrahedron letters

Synthesis of 2-nitroindoles via the Sundberg indole synthesis

ET Pelkey, GW Gribble

Index: Pelkey, Erin T.; Gribble, Gordon W. Tetrahedron Letters, 1997 , vol. 38, # 32 p. 5603 - 5606

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Citation Number: 58

Abstract

A three-step sequence has been developed for converting o-nitrobenzaldehydes into 2- nitroindoles. The key step involves the thermolysis of 2-(o-azidophenyl) nitroethylene (10) in xylenes which gives 2-nitroindole (4) in 54% yield, akin to the classic Sundberg indole synthesis. This procedure has also been utilized to synthesize 5, 6-dimethoxy-2-nitroindole (14).