Fused Imidazoles: A Novel Synthesis of Imidazo[1,2-<i>b</i>][1,2,4]triazole and Imidazo[5,1-<i>f</i>]-[1,2,4]triazine Derivatives
作者:Pedro Molina、Angeles Lorenzo、Enrique Aller
DOI:10.1055/s-1989-27406
日期:——
The reaction of 1-amino-2-methylthio-4-phenylimidazole with isothiocyanates, followed by treatment with methyl iodide and heating in ethanol affords 1,6-disubstituted 2-methylthio-1H-imidazo[1,2-b] [1,2,4]triazoles. Starting from the same aminoimidazole, a sequence consisting of N-phosphoranylidenation with triphenylphosphine dibromide, replacement of the phosphoranylidene group by an α-chlorobenzylidene group by reaction with benzoyl chlorides, Cl/N3 exchange with sodium azide, and reaction of the resultant N-(α-azidobenzyl) derivate with triphenylphosphine affords the N-[α-(triphenylphoranylidenamino)benzyl] derivatives which, on reaction with isocyanates are converted into 2,4,5,7-tetrasubstituted imidazo[5,1-f] [1,2,4]triazines.
1-氨基-2-甲基硫-4-苯基咪唑与异硫氰酸酯反应,再经碘化甲基处理并在乙醇中加热,得到了1,6-二取代的2-甲基硫-1H-咪唑[1,2-b][1,2,4]三氮唑。从相同的氨基咪唑出发,经过与溴化三苯基膦的N-磷烯基化反应,再通过与苯甲酰氯反应用α-氯苄烯基取代磷烯基基团,接着与氮化钠进行Cl/N3交换,最后将所得的N-(α-叠氮苄基)衍生物与三苯基膦反应,得到了N-[α-(三苯基磷烯基氨基)苄基]衍生物,这些衍生物与异氰酸酯反应,可转化为2,4,5,7-四取代的咪唑[5,1-f][1,2,4]三氮唑。