Synthesis of Polysubstituted Quinazolinones from the Continuous Reaction of alpha-Cyano Disulfide Ketene

alpha-Cyano disulfide ketene 1, obtained from the reaction of alpha-methyl cyano-acetate, carbon disulfide and methyl iodide, condensated with acetophenone 2 to provide 3-cyano-2H-pyran-2-ketones 3, then ring transformation of 3 and malononitrile under base afforded aromatic o-amino dinitriles 4, and 4 reacted with ketone 5 to give the polysubstituted quinazolinone 6. This continuous reaction for the convenient synthesis of polysubstituted quinazolinone 6 has the follow advantages: simple raw materials, mild reaction condition, and simple operation.