6-Trifluoromethyl-1,2,4-triazines (2), 3-trifluoromethyl-5-pyrazolones (3), or 5-trifluoromethyl-3-hydroxypyrazoles (4) are selectively btained in good yields through the regioselective attack of phenylhydrazine on mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates (1), depending on the nature of the reaction solvent and temperature.
通过苯
肼的区域选择性攻击,有选择地获得了6-三
氟甲基-
1,2,4-三嗪(2),3-三
氟甲基-5-
吡唑啉酮(3)或5-三
氟甲基-3-羟基
吡唑(4)。取决于反应溶剂的性质和温度,中离子的4-三
氟乙酰基-1,3-
恶唑鎓5-酸酯(1)。