Reaction of 1-substituted 4-acyl-5-hydroxy-3-methyl-1H-pyrazoles (2) with hydroxylamine gives the corresponding "oximes" 3, which are mainly present as (Z)-2,4-dihydro-4-[(hydroxyamino)methylene]-3H-pyrazol-3-ones. Treatment of compounds 3 with trichloroacetyl isocyanate/potassium carbonate in anhydrous diethyl ether affords 7-methyl-1,5,6-triazaspiro[2.4]hepta-1,6-dien-4-ones (4). The structure of
1-取代的4-酰基-5-羟基-3-甲基-1H-
吡唑(2)与
羟胺的反应产生相应的“
肟” 3,其主要以(Z)-2,4-二氢-4-的形式存在[(羟基
氨基)亚甲基] -
3H-吡唑-3-酮。用三
氯乙酰基
异氰酸酯/
碳酸钾在无
水乙醚中处理化合物3,得到7-甲基-1,5,6-三氮杂螺[2.4]庚-1,6-二烯-4-酮(4)。通过单晶X射线分析(4f,4h)阐明了化合物4的结构,并通过NMR光谱研究证实了((1)H,(13)C)。