One-Pot Three-Component Synthesis of 1,4-bis[thiazolo[4,5-d]pyrimidin-7(6 H )-one]piperazine derivatives

Abstract

A simple one-pot efficient method is described for the synthesis of 1,4-bis[thiazolo[4,5-d]pyrimidin-7(6H)-one] piperazine derivatives by a domino three-component process involving an aza-Wittig reaction/heterocyclisation in the presence of sodium ethoxide as catalyst. Ethyl 4-[(triphenylphosphanylidene)amino]-2,3-dihydro-3-phenyl-2-thioxothiazole-5-carboxylate reacted with aromatic isocyanates to give carbodiimide intermediates. This was followed by the addition of piperazines to give the corresponding guanidine intermediates. The guanidine intermediates were then cyclised in the presence of catalytic amount of sodium ethoxide to give 1,4-bis[thiazolo[4,5-d]pyrimidin-7(6H)-one]piperazine derivatives in good yields.