Copper-catalyzed consecutive reaction to construct quinazolin-4(3H)-ones and pyrido[2,3-d]pyrimidin-4(3H)-ones

An efficient and practical copper-catalyzed consecutive synthesis of quinazolin-4(3H)-ones and pyrido[2,3-d]pyrimidin-4(3H)-ones from easily available 2-halobenzamides (or 2-halonicotinamides), aldehydes, and sodium azide has been developed, which gave the corresponding target products in 50–95% yields for 29 examples. This remarkable consecutive process involved sequential copper-catalyzed SNAr, reduction, cyclization, and oxidation. Notably, this work would provide a novel synthetic strategy for bioactive molecules containing quinazolinone class skeletons.