SYNTHESES OF INDOLYL-4(3H)-QUINAZOLINONES

2-(1H-Indol-2-yl)-4(3H)-quinazolinones (10, 11) and hoxycarbonyl-1H-in dol-3-yl)-4(3H)-quinazolin-4-one (15) are prepared by the Fischer indo lization of 2-(1-phenylhydrazonoalkyl)- (8,9) and razono-2-ethoxycarbo nylethyl)-4(3H)-quinazolinones (14), respectively, by heating in PPA. When 2-phenylhydrazone derivative (14) is heated in 85% phosphoric aci d at 180-degrees-C, besides indolization ester hydrolysis and decarbox ylation also occurred to yield 2-(1H-indol-3-yl)-4(3H)-quinazolinone ( 16). The 3-(1H-indol-3-yl)-4(3H)-quinazolinone (24) is prepared either from the isomeric 3-indolyl derivatives of anthranilamide (21, 23) by heating in 98% formic acid, or in ''one pot'' procedure from (N-methy l-N-phenylamino)ethyl]-4(3H)-quinazolinone (17) by heating in 98% form ic acid in the presence of a few drops of conc. hydrochloric acid. The reaction mechanism is discussed.