Ag/SiO2 as a recyclable catalyst for the facile green synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-ones

Abstract

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/SiO 2 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/SiO 2 , was fully characterized and is reusable without loss of activity for up to seven cycles with marginal activity loss. Graphical AbstractN O O CH 3 OEt O O NH 2 OH.HCl CHO R R Ag/SiO 2 H 2 O / R.T, 1h 4a-m Electronic supplementary material The online version of this article (

Concentrated Solar Radiation Aided Green Approach for Preparative Scale and Solvent‐Free Synthesis of 3‐Methyl‐4‐(hetero)arylmethylene Isoxazole‐5(4H)‐ones

“…Literature studies reveals scientists have developed one‐pot multicomponent synthesis of 3‐methyl‐4‐arylmethylene‐isoxazole‐5(4H)‐one through reaction of ethyl acetoacetate, hydroxylamine hydrochloride and arylaldehydes using numerous catalyst such as boric acid, DOWEX 50WX4, potassium phthalimide, pyridinium p‐toluenesulphonate (PPTS), citric acid, Ag/SiO2 , sodium sulphide, DABCO etc. Other methods such as microwave irradiation, ultrasonication, are also reported.…”

Synthesis and characterization of nanocrystalline hydroxyapatite and its catalytic behavior towards synthesis of 3,4‐disubstituted isoxazole‐5(4H)‐ones in water

“…Ag/SiO 2 /water/R.T. [42] 60 93 2-HSBA/water/R.T. [48] 110 87 Nano-MMT-Sn/water/us/ 30°C [50] 40 92 TBAP/water/R.T.…”

“…[21][22][23] It also has biological properties, for example anti-obesity, [24] anti-inflammatory, [25] antifungal, [26] anticancer, [27] antitumor [28] and antibacterial. [29] A number of catalysts used to synthesize such compounds include sulfated polyborate, [30] sodium saccharin, [31] tetrabutylammonium perchlorate (TBAP)/ sodium oxalate or glycine, [32] Fe 2 O 3 nanoparticles, [33] Ni (OAc) 2 ·H 2 O, [34] citric acid, [35] sodium silicate, [36] sodium benzoate, [37] sodium sulfide, [38] boric acid, [39] potassium phthalimide (PPI), [40] phthalimide N-oxyl salts, [41] Ag/SiO 2 , [42] DABCO, [43] pyridine, [44] sodium citrate, [45] N-bromosuccinimide (NBS), [46] potassium hydrogen phthalate (KHP), [47] 2-hydroxy-5-sulfobenzoic acid (2-HSBA), [48] Dowex1-x8OH resin, [49] montmorillonite K10 supported Sn II composite (Sn II -MontK10), [50] and imidazole. [51] However, most of the techniques and methods mentioned above have limitations and problems, i.e.…”

Our Contributions in Synthesis of Diverse Heterocyclic Scaffolds by Using Mixed Oxides as Heterogeneous Catalysts

“…Silver promotes different types of organic reactions like Oxidations, and alkylation reactions . Based on the above importance we synthesised 5 wt% of Ag/ SiO 2 mixed oxide to synthesise 9 novel isoxazole‐ 5(4H)‐one derivatives, by reacting equimolar ratios of hydroxylamine, ethyl acetoacetate and aldehyde in water as a solvent in presence of 30 mg of catalyst at room temperature (Scheme ). The reaction takes place in <1 h. This is due to its high surface area of 189 m 2 /g, which facilitate the reaction on the surface to achieve high yields of 88–93 % yields.…”