A new route for the synthesis of isomeric benzo[b]furoindoles

Abstract

A new synthesis of 1H-benzo[b]furo[3,2-f]- and 1H-benzo[b]furo[2,3-e]indoles was described. The corresponding ring-fused isatins, synthesized by the Sandmeyer reaction, were utilized as initial compounds. The reduction of the last to the unsubstituted benzo[b]furoindoles depends both on the nature of the substituent, and on the reaction conditions.