Pyridines; XVI. Reactions of N1-(Arylethenyl)benzamidines with Isocyanates and Phenyl Isothiocyanate. A Facile Synthesis of N1-(1,2-Diarylethenyl)-N2-(alkyl- or arylaminocarbonyl)benzamidines and Substituted 2-Oxo- or 2-Thioxo-1,2,3,4-tetrahydro-1,3-5-triazines

Article abstract of DOI:10.1055/s-1988-27599

N¹-(1,2-Diarylethenyl)-N²-(alkyl- or arylaminocarbonyl)benzamidines are easily prepared in good to high yields (61-90percent) by reaction of various isocyanates with N¹-(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 quinuclidine the resultant N¹,N²-disubstituted benzamidines are cyclized to give substituted 2-oxo- or 2-thioxo-1,2,3,4-tetrahydro-1,3,5-triazines in yields of 31-92percent.