A series of new 2-substituted tetrahydrobenzo[4′,5′]thieno[3′,2′:5,6]pyrido[4,3-d] pyrimidin-4(3H)-ones 5 has been designed and synthesized via an aza-Wittig reaction. Iminophosphorane 3a or iminophosphorane 3b reacted with 4-Cl-phenyl(or 4-F-phenyl) isocyanate to give carbodiimide 4a or carbodiimide 4b , which were further treated with phenols to cyclize to give compounds 5 in presence of a catalytic amount of K2CO3. The structures of compound 5 have been confirmed by...
