Preparation of nucleoside–pyridine hybrids and pyridine attached acylureas from an unexpected uracil ring-opening and pyridine ring-forming sequence

Abstract Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids ( 4 ) or pyridine attached acylureas ( 5 ) were selectively and efficiently prepared from the reaction of 2′-deoxyuridin-5-yl-methylene malononitrile ( 1 ), malononitrile ( 2 ) and thiophenol ( 3 ) or from an unexpected uracil ring-opening and pyridine ring-forming sequence via the reaction of 1 and 3 . It is the first time such a sequence has ever been reported.