Efficient Preparation of 2, 2′-Disubstituted-3, 3′-(1, 4-phenylene)bis-thienopyrimidin-4-ones Based on an aza-Wittig Reaction

Abstract

Tandem aza-Wittig reaction of iminophosphorane with 1, 4-phenylene diisocyanate followed by intramolecular heteroconjugate addition annulation after addition of a nucleophilic reagent (amine, phenol, and alcohol), in the presence of catalytic K2CO3 or NaOR, gives selectively the functionalized substituted 2, 2′-di(alkylamino, aryloxy)-3, 3′-(1, 4-phenylene)bis(thieno[3, 2-d]pyrimidin-4(3H)-ones) and 2, 2′-di(alkylamino or alkoxy)-3, 3′-(1, 4-phenylene)bis(3, 5, 6, 7-tetrahydro-4H-cyclopenta[4, 5]thieno[2, 3-d]pyrimidin-4-ones).