有機硫黄化合物の合成化学的研究(第7報) : 硫黄の存在下, 活性メチル, アミンおよびアントラニール酸による4(3H)-Quinazolinone Cyclization

抄録

Thiopilinanilides were found to react with anthranilic acid, in the presence of amines, and formed a 4 (3H)-quinazolinone ring in a good yield. In this case, there is a possibility that aromatic primary amines might react first with thiopicolinanilides to form amidines which might take part directly in cyclization to 4 (3H)-quinazolinone. Examinations were therefore made on the reaction of the corresponding N, N'-diphenylpicolylamidines and anthranilic acid, and it was thereby found that amidines show a similar reactivity as thiopicolinanilides and formed 4 (3H)-quinazolinones in almost the same yield. Therefore, thiopicolinanilide and aniline were reacted and formation of amidine during the reaction was examined, and the formation of amidine under the reaction conditions thought to be responsible for the above reaction was only about 11%. Consequently, it was assumed that amidine formation was not an important factor in the said reaction mechanism. Active methyl compounds, aromatic primary amines, and anthranilic acid were reacted in the presence of sulfur to examine direct cyclization to 4 (3H)-quinazolinone and the reaction was found to afford 2-pyridyl-3-phenyl-4 (3H)-quinazolinone derivatives quite easily.