KHSO 4 promoted practical synthesis of quinazolin-4( 3H )-ones and benzothiadiazine 1,1-dioxides

A broad scope of quinazolin-4(3H)-ones or benzothiadiazine 1,1-dioxides was obtained via a transition-metal free and convenient method. This approach involving KHSO4 promoted cyclization and dehydration between diverse functionalized 2-aminobenzamides or 2-aminobenzenesulfonamides and N, N-dimethylformamide derivatives. The protocol offers moderate to excellent yields (45%-93%) under mild condition in a short of reaction time of 6 hours. The use of an environment-friendly and less expensive catalyst KHSO4 also makes this protocol more attractive.