A convenient synthesis of new pyridothienopyrimidin-4 (3H) ones and pyridothienopyrimidin-2, 4(1H, 3H) diones

New derivatives of 2-substituted pyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4(3H) ones and 3-substituted pyrido[3',2':4,5]thieno[3,2-d]pyrimidin-2,4(1H,3H) diones have been prepared by base catalyzed cyclocondensation of ethyl-3-aminothieno[3,2-b]pyridine-2carboxylate with aryl nitriles and aryl- or alkyl isocyanates respectively.