N-Alkylhydrazones of aliphatic ketones in the synthesis of 1,3,4-trisubstituted non-symmetric pyrazoles
摘要:
Reactions of N-alkylhydrazones of aliphatic ketones with the Vilsmeier-Haack reagent (DMF-POCl3) were evaluated as a promising approach toward the synthesis of trisubstituted non-symmetric pyrazoles. It was found that either 1,3,4-trialkylpyrazoles or 1,3-dialkylpyrazole-4-carbaldehydes could be obtained in these transformations in high yields (72-83%), in a regioselective manner. (C) 2014 Elsevier Ltd. All rights reserved.
一个复杂的固态工艺的级联通过温度的变化开始被发现为heterospin络合物[铜(HFAC)2大号我/ ET ]形成在铜的反应(II)六氟乙酰丙酮[铜(HFAC)2 ]稳定nitronyl氮氧化物2-(1-甲基-3-乙基-1 H-吡唑-4-基)-4,4,5,5-四甲基-4,5-二氢-1 H-咪唑-3-氧化物-1-氧基(L Me / Et)。将化合物冷却至260 K以下会引发固态化学反应,从而导致链解聚并形成成对的异旋复合物[Cu(hfac)2 L Me / Et 2 ] [[Cu(hfac)2 ] 3L Me / Et 2 ]。在下面144 K温度进一步降低导致伴随着有效磁矩到2.24μ的急剧下降从2.52自旋过渡乙。加热化合物时,作用顺序相反:首先,磁矩突然增加,然后该对分子的分子簇聚集成聚合物链。两个磁滞回线对应于这种由温度引起的结构转换的级联,取决于实验依赖性μeff(T):一个在高(T