Eco-Friendly Atom-Economical Synthesis of 2-Substituted-benzo[d]thiazoles and 2-Substituted-benzo[d]oxazoles Using 2-Acylpyridazin-3(2H)-ones.

Efficient and green syntheses of heterocycles are of great importance. In this work, we have demonstrated the synthesis of benzo[d]thiazoles and benzo[d]oxazoles using 2-acylpyridazin-3(2H)-ones as acyl transfer agents under transition-metal-free and eco-friendly conditions. It is worthy to note that the reaction is efficient, green, and economical, and will find several applications in organic synthesis, medicinal chemistry, and industrial chemistry.