... Thus, when anthranilic acids (5) were reacted with acid chlorides (10) in pyridine at 0 °C, benzooxazinones (6) were obtained as crystalline products. The subsequent reflux with amines (11) and catalytic amount of pTSA in toluene gave a mixture of quinazolinones (7) and uncyclized diamides (8), which were converted to products (7) by heating in acetic acid and concentrated sulfuric acid (9:1) at 100 °C for 15 min. ...