PREPARATIVE ELECTROREDUCTION OF 5-AND 6-NITROBENZOTHIOPHENES IN ACIDIC AND BASIC HYDROMETHANOLIC SOLUTION

摘要

We have shown that the electroreduction of 5- and 6-nitroindoles (1,X=NH or NCH_3) and 5- and 6-nitrobenzofuranes ( 1,X=O),at Hg,in acidic (HX 0.15 M,pH = 0.3,X = HSO_4,Br) aqueous methanol (MeOH-H_2O 95:5,v/v) gives substituted amino derivatives 2 and the corresponding amines 3 [1-4].The formation of substituted compounds 2 has been explained by attack of a nucleophile on diiminoquinone 4 (Y = OH and/or H) and quinonemethane imine 5 (Y = OH and/or H) resulting from dehydration of dihydroxylamines and/or hydroxylamines.