Iminophosphorane-mediated efficient synthesis of new tricyclic 3,5-dihydro-1,2,3-triazolo[4,5-d]-1,2,4-triazolo[1,5-a]pyrimidin-9-ones
作者:Jun-Feng Zhao、Chang Xie、Sheng-Zhen Xu、Ming-Wu Ding、Wen-Jing Xiao
DOI:10.1039/b513715b
日期:——
The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, reacted with hydrazine to give selectively 6-amino-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 5. Compounds 5 were further transformed to iminophosphoranes 6 by reaction with triphenylphosphine, hexachloroethane and triethylamine. A tandem aza-Wittig reaction of iminophosphorane 6 with isocyanate or acyl chloride generated previously unreported 3,5-dihydro-1,2,3-triazolo[4,5-d]-1,2,4-triazolo[1,5-a]pyrimidin-9-ones 10 or 12 in satisfactory yield. X-ray structure analysis of 10g verified the proposed structure and the reaction selectivity.
通过亚氨基磷烷 1 与芳香族异氰酸酯的偶氮-维蒂希反应得到的碳化二亚胺 2 与肼反应,可选择性地得到 6-氨基-7H-1,2,3-三唑并[4,5-d]嘧啶-7-酮 5。化合物 5 通过与三苯基膦、六氯乙烷和三乙胺反应,进一步转化为亚氨基磷烷 6。亚氨基磷烷 6 与异氰酸酯或酰氯的串联偶氮-维蒂希反应生成了之前未报道过的 3,5-二氢-1,2,3-三唑并[4,5-d]-1,2,4-三唑并[1,5-a]嘧啶-9-酮 10 或 12,收率令人满意。10g 的 X 射线结构分析验证了所提出的结构和反应选择性。