Quinazolinone Synthesis through Base-Promoted S(N)Ar Reaction of ortho-Fluorobenzamides with Amides Followed by Cyclization

[Image: see text] A transition-metal-free synthesis of quinazolin-4-ones by Cs(2)CO(3)-promoted S(N)Ar reaction of ortho-fluorobenzamides with amides followed by cyclization in dimethyl sulfoxide has been developed. The present procedure can provide efficient synthetic methods for the formation of both 2-substituted and 2,3-disubstituted quinazolin-4-one rings depending on the use of easily available starting materials and an efficient, one-pot protocol for the synthesis of the marketed drug product of methaqualone.