Facile Synthesis of Benzo[ d ]azol-2(3 H)-ones Using 2-Phenoxycarbonyl-4,5-dichloropyridazin-3(2 H)-one as Green CO Source

Developing eco-friendly, stable, and easy-to-handle acyl sources is of great importance in synthetic and green chemistry. This study describes the synthesis of benzo[d]azol-2(3H)-ones such as benzo[d]thiazol-2(3H)-ones, benzo[d]oxazol-2(3H)-ones, and benzo[d]imidazol-2(3H)-ones using 2-phenoxycarbonyl-4,5-dichloropyridazin-3(2H)-one in one pot. The reaction reported is carried out under neutral or acidic conditions in the presence of zinc or sodium bicarbonate to give the corresponding heterocycles in good to excellent yields. The reaction uses a solid stable carbonyl source that is a recyclable functional-group carrier, pyridazin-3(2H)-one.