The synthesis of o‐Amino‐N‐substituted benzamides and 3‐substituted 2,4 (1H,3H)‐quinazolinediones from isatoic anhydride

The reaction of isatoic anhydride with sterically hindered amines in DMF or DMSO, and subsequent treatment of the o‐amino‐N‐substituted benzamides thus produced with phosgene, gives high yields of 2,4(1H,3H)‐quinazolinediones with branched alkyl groups in the 3‐position.