An efficient one-pot synthesis of 3-glyoxylic acids of electron-deficient substituted azaindoles by ionic liquid imidazolium chloroaluminate-promoted Friedel-Crafts acylation

An efficient, one-pot Friedel-Crafts acylation/hydrolysis reaction promoted by the acidic ionic liquid 1-ethyl-3-methylimidazolium chloroaluminate (generated from 1-ethyl-3-methylimidazolium chloride (EmimCl) and aluminum chloride (X(AlCl(3)), Mole fraction X = 0.75) for the formation of 3-glyoxylic acid derivatives of electron-deficient, substituted 4- and 6-azaindoles is described. (C) 2008 Elsevier Ltd. All rights reserved.