An environment-friendly synthesis of 4(3H)-quinazolinones

4(3H)-Quinazolinones, a class of important heterocycles, are used extensively in various fields. Although there are a number of synthetic approaches, all of them use catalysts, solvents, chemical oxidants, and/or reagents harmful to the environment when released in large quantities. An environment-friendly, catalyst-free, solventless, one-step synthesis of 4(3H)-quinazolinones is presented. The process involves heating of aldehydes and anthranilamides under air as cheap oxidant and as key promoter of reaction. The protocol is suitable for both aromatic and aliphatic aldehydes. This novel synthetic method may be applied to a wide range of educts, offering high yields at low cost while characterized by minimum environmental impact.