An efficient and facile green method for synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-one (4a-m) via room temperature reaction of hydroxylamine, ethylacetoacetate and substituted aromatic aldehydes is designed, using Ag/SiO2 as catalyst with water as solvent. This protocol offers several advantages, such as it being a benign, energy conserving and eco-friendly reaction with products obtained in excellent yields (88–93 %). The reaction requires relatively short reaction times (< 1 h), a simple workup procedure with good atom efficiency and easily recoverable catalyst. The heterogeneous catalyst, Ag/SiO2, was fully characterized and is reusable without loss of activity for up to seven cycles with marginal activity loss.
一种高效且简便的绿色合成方法被设计用于在室温下通过氢氧胺、
乙酰乙酸乙酯和取代芳醛的反应,合成3-甲基-4-(苯基)亚烯基
异恶唑-5(4H)-酮(4a-m),使用Ag/SiO2作为催化剂,以
水作为溶剂。该方法具有多个优点,例如反应温和、节能且环保,所获得的产品产率优异(88–93%)。反应所需时间相对较短(< 1小时),操作流程简单,具有良好的原子效率,并且催化剂可轻松回收。异相催化剂Ag/SiO2经过充分表征,在七个循环内可重复使用,且活性损失极小。