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[摘要]：A simple three-component reaction and efficient method is described for the synthesis of 1,4-bis[triazolo[4,5-d]pyrimidin-7(6H)-one]piperazines by a sequential three-component process involving an aza-Wittig reaction/heterocyclization in the presence of sodium ethoxide as catalyst. The iminophosphorane 1 reacted with aromatic isocyanate gave carbodiimides 2, followed by addition of piperazine derivatives to give the corresponding guanidine intermediates 3. The guanidine intermediates were cyclized in the presence of catalytic amount of sodium ethoxide to give 1,4-bis[triazolo[4,5-d]pyrimidin-7(6H)-one]piperazines 4 in good yields. |
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