Electrochemical NaI/NaCl-mediated one-pot synthesis of 2-aminobenzoxazoles in aqueous media via tandem addition–cyclization†
An electrochemical synthesis of 2-aminobenzoxazoles from 2-aminophenols and isothiocyanates was successfully developed in a one-pot fashion. Using inexpensive and widely available NaI and NaCl co-operatively in catalytic amounts, our electrosynthesis approach provided various 2-aminobenzoxazole products in moderate to high yields in an open-flask type undivided cell without using any external supporting electrolyte and base. The protocol can be applied to the synthesis of 2-aminobenzothiazoles from the corresponding 2-thiophenols in moderate yields. This protocol has many benefits. It is metal-free and highly scalable and uses inexpensive mediators and EtOH/water as an environmentally friendly solvent under mild conditions.