PTSA catalyzed solid phase synthesis of some 2-arylbenzothiazoles : An expeditious, mild and greener protocol

A mild, expeditious and greener protocol for the preparation of various 2-substituted benzothiazoles (3) has been developed. The reaction of o-aminothiophenol with various substituted aromatic aldehydes proceeds smoothly in the presence of p-toulene sulfonic acid (PTSA) as a solid organocatalyst at room temperature. The products were obtained in excellent yields in very short time. Mild reaction conditions, clean reaction media, simple workup and easy purification are advantages of this protocol.