N 1-(1,2-Diarylethenyl)-N 2-(alkyl- or arylaminocarbonyl)benzamidines are easily prepared in good to high yields (61-90%) by reaction of various isocyanates with N 1-(1,2-diarylethenyl)benzamidines in tetrahydrofuran. When this addition reaction of the isocyanates (and also of phenyl isothiocyanate) with the amidines is performed in boiling toluene in the presence of catalytic amounts of quinuolidine the resultant N 1,N 2-disubstituted benzamidines are cyclized to give substituted 2-oxo- or 2-thioxo-1,2,3,4-tetrahydro-1,3,5-triazines in yields of 31-92%.
N 1-(1,2-二芳基
乙烯基)-N 2-(烷基或芳基
氨基羰基)
苯甲脒通过各种
异氰酸酯与 N 1-(1,2-二芳基
乙烯基)
苯甲脒在
四氢呋喃中的反应很容易制备,产率高达 61-90%。当
异氰酸酯(以及异
硫氰酸苯酯)与酰胺在沸腾的
甲苯中,在催化量的
喹啉存在下进行加成反应时,生成的 N 1,N 2-二取代
苯甲脒会环化生成取代的 2-氧代或 2-
硫代-1,2,3,4-四氢-
1,3,5-三嗪,产率为 31-92%。