Three-Component One-Pot Construction of 2-Aryl-4H-benzo[4,5]thiazolo[3,2-a]pyrimidines Using Solid Calcium Carbide as a Surrogate of Gaseous Acetylene

Abstract

A concise method for the construction of 2-aryl-4H-benzo[4,5]thiazolo[3,2-a]pyrimidines using solid calcium carbide instead of gaseous acetylene as an alkyne source and 2-aminobenzothiazoles and aromatic aldehydes as substrates through one-pot three-component cascade reactions is described. The salient features for this protocol are the use of an inexpensive and easy-tohandle alkyne source, noble-metal-free condition, wide substrate scope and functional tolerance, satisfactory yield, and simple workup procedure.

One-Pot Synthesis of 1,2,3-Triarylindoles through Cascade Reactions Using Calcium Carbide, Iodoarenes, and Aromatic Amines

“…Fortunately, the recent research reported that calcium carbide could directly use as solid alkyne source instead of gaseous acetylene in important organic synthesis . Our recent work has also focused on calcium carbide as an alkyne source and reported the synthesis of many active heterocycles …”