1977 年 97 巻 7 号 p. 808-815
In continuation of previous studies on high-temperature fusion reaction of anthranilic acid (II) and primary amines to obtain 4 (3H)-quinazolinones in one step, o-toluidine was used as the amine and II was reacted with 4-picoline (Ia), in the presence of sulfur and 3-phenyl-2-(4-pyridyl)-4 (3H)-quinazoline (IIIa) was obtained with 2-(4-pyridyl)-3-(o-tolyl)-4 (3H)-quinazolinone (V). In order to clarify the formation of these products, Ia and II alone were reacted in the presence of sulfur and it was found that the use of two-fold moles of II resulted in the increased yield of IIIa but, at the same time, 2-(4-pyridyl)-benzothiazole (IVa) was formed. In order to elucidate this result, the same reaction was carried out with seven kinds of compound having an active methyl group.