Synthesis of 4-arylaminoquinazolines and 2-aryl-4-arylaminoquinazolines from 2-aminobenzonitrile, anilines and formic acid or benzaldehydes

2-Aminobenzonitrile treated with anilines in the presence of aluminium chlo ride gave respective 2-amino-N-arylbenzamidines. 4-Arylaminoquinazolines la cking a substituent at the 2 position were obtained directly by heating 2-a mino-N-arylbenzamidines in formic acid; in similar conditions other carboxy lic acids did not react with the amidines. The latter when treated with aid ehydes afforded 2-aryl-4arylimino-1H-2,3-dihydroquinazolines readily oxidiz able by potassium permanganate to 2-aryl-4-arylaminoquinazolines. (C) 2000 Elsevier Science Ltd. All rights reserved.