Spiro-Fused (C2)-Azirino-(C4)-pyrazolones, a New Heterocyclic System. Synthesis, Spectroscopic Studies and X-ray Structure Analysis<sup>1</sup>
作者:Wolfgang Holzer、Rosa M. Claramunt、Marta Pérez-Torralba、Davide Guggi、Thomas H. Brehmer
DOI:10.1021/jo030131t
日期:2003.10.1
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)。