An efficient route for synthesis of 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4(3H)-one

Abstract The carbodiimide 2 , obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates, reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2- d ]pyrimidin-4(3 H )-ones 4 and 5 . The formation mechanism of the title compounds has been investigated.