The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane I with aromatic isocyanates, reacted with secondary amines or ROH to give 5-dialkylamino or 5-alkoxy 7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in the presence of a catalytic amount of EtONa in a mixed solvent (CH 2 Cl 2 -ROH). Reactions of 2 with phenols in presence of catalytic potassium carbonate in MeCN gave 5-aryloxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4 in satisfactory yields.

中文翻译：

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5-取代的 3,6-Dihydro-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 的碱催化高效合成

碳二亚胺 2 由亚氨基正膦 I 与芳香族异氰酸酯的 aza-Wittig 反应获得，与仲胺或 ROH 反应生成 5-二烷基氨基或 5-烷氧基 7H-1,2,3-三唑并[4,5-d]嘧啶-在混合溶剂 (CH 2 Cl 2 -ROH) 中催化量的 EtONa 存在下的 7-ones 4。在 MeCN 中催化碳酸钾存在下，2 与酚类反应以令人满意的收率得到 5-aryloxy-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 4。