TsNBr2 Mediated Synthesis of 2-Acylbenzothiazoles and Quinoxalines from Aryl Methyl Ketones under Metal Free Condition

摘要

An efficient one pot strategy has been developed for the synthesis of 2-acylbenzothiazoles and quinoxalines from aryl methyl ketones.A variety of heterocycles of these two categories could be prepared in a two-step sequence in excellent yields.The reaction was performed starting from aromatic ketones via an aryl gloxal intermediate which,on further condensation with 2-aminobenzenethiol or o-phenylenediamine,produces the corresponding heterocyclic skeleton.Aromatic ketones are initially treated with TsNBr2 in DMSO at 65°C for 3 h and the crude reaction mixture was treated with 2-aminobenzenethiol(at 80°C)or o-phenylenediamine(at RT)to generate the final compound.