Regioselective Synthesis of Novel FunctionalizedPyrano[2′,3′:4,5]pyrimido[1,6-b][1,2,4,5]triazaphosphepines

The reactions of 6-acetyl-3-amino-4-imino-7-methyl-5-phenyl-3,5-dihydro-4H-pyrano[2,3-d]pyrimidine with triethyl phosphite and some electrophilic reagents, namely 1,2-dibromoethane, oxalyl chloride, chloroacetyl chloride, and ethyl chloroacetate, were studied. These one-pot three-component reactions regioselectively afforded four new 11-acetyl-2-ethoxy-10-methyl-12-phenylpyrano[2′,3′:4,5]pyrimido[1,6-b][1,2,4,5λ5]triazaphosphepin-2-ones in 69–73% yields.