A Practical Access to Novel 2-Amino-5-arylidene-1,3-thiazol-4(5H)-ones via Sulfur/Nitrogen Displacement under Solvent-Free Microwave Irradiation.

Abstract A new effective approach to the synthesis of a small library of 2-amino-5-arylidene-1,3-thiazol-4(5 H )-ones was reported using solvent-free reaction conditions under microwave irradiation. In the first step, rhodanines were subjected to Knoevenagel condensation with aryl aldimines according to a facile one-pot protocol. Then the (5 Z )-5-arylidene rhodanine derivatives were transformed directly into the corresponding 2-amino-1,3-thiazol-4(5 H )-ones by sulfur/nitrogen displacement reaction under microwaves with retention of configuration and good overall yields.