Fe/S-Catalyzed synthesis of 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles via redox condensation of o-nitrophenols with acetophenones and methylquinolines

An Fe/S catalyst generated in situ from FeCl2 center dot 4H(2)O and elemental sulfur S-8 in the presence of a tertiary amine as a base was found to catalyze efficiently a 6e(-) redox condensation of o-nitrophenols with acetophenones and methylquinolines. The condensed products 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles were obtained in reasonable yields with water as the only byproduct at a temperature as low as 80 degrees C.

Automated summary

A Fe/S catalyst generated in situ from FeCl2•4H2O and elemental sulfur S-8 in the presence of a tertiary amine efficiently catalyzed a 6e(-) redox condensation of o-nitrophenols with acetophenones and methylquinolines, giving reasonable yields of condensed products 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles with water as the sole byproduct at a low temperature of 80 degrees C.