New heterocyclization reactions for the preparation of fused [1,2,4]triazoles: synthesis of 1,2,4-triazolo[4,3-b][1,2,4]triazole derivatives from 4-amino-1,2,4-triazoles and carbodi-imides or via iminophosphoranes and disubstituted thioureas
作者:Pedro Molina、Mateo Alajarín、Alicia Ferao、Me. Jesús Pérez de Vega
DOI:10.1039/p19870002667
日期:——
(3)—(10) undergo base-catalysed cyclization to give the 1,2,4-triazolo[4,3-b][1,2,4]triazoles (11)—(18). Sequential treatment of triazolo-triazoles (15)—(18) with methyl trifluoromethanesulphonate and triethylamine leads to the conjugated mesomeric betaines (23)—(26); on the other hand; sequential treatment of triazoles (7) and (10) with methyl trifluoromethanesulphonate and triethylamine leads to the
已经制备了许多1,2,4-三唑并[4,3- b ] [1,2,4]三唑衍生物。4-氨基-2-甲基-5-甲硫基-2- ħ -1,2,4-三唑-3-(4 ħ) -酮(1)反应以diarylcarbodi -酰亚胺,得到相应的4-(Ñ,Ñ ' -二芳基)胍基-2-甲基-5-甲硫基-2 H -1,2,4-三唑-3(4 H)-ones(3)-(6)。2-甲基-5-甲基硫代-4-三苯基磷酰亚氨基氨基-2 H -1,2,4-三唑-3(4 H)-硫酮(2)与N,N'-二芳基硫脲的反应生成相应的4- (N,N'-二芳基)胍基-2-甲基-5-甲硫基-2 H -1,2,4-三唑-3(4 H)-硫酮(7)–(10)。化合物(3)-(10)经历碱催化的环化,得到1,2,4-三唑并[4,3- b ] [1,2,4]三唑(11)-(18)。用三氟甲磺酸甲酯和三乙胺依次处理三唑-三唑(15)-(18),得到共轭的美苏木甜菜碱(23)-(26)。另一方面;