Acetyl chloride → 5-Methyl-3-(4-nitrobenzyl)-1,2,4-oxadiazole

Beteiligte Stoffe

Reaktionsschritte

To a mixture of N′-hydroxy-2-(4-nitrophenyl)ethanimidamide (2.38 g) and N,N-dimethylacetamide (30 mL) was added acetyl chloride (0.96 g) at room temperature and the mixture was stirred at room temperature for 15 hrs. Water was poured into the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated. A mixture of obtained residue and xylene (100 mL) was heated under reflux for 24 hrs. The reaction mixture was concentrated and ethyl acetate was added to the obtained residue. The mixture was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography to give 5-methyl-3-(4-nitrobenzyl)-1,2,4-oxadiazole as orange crystals (1.00 g, yield 37%) from a fraction eluted with hexane-ethyl acetate (4:1-3:1, v/v). Recrystallization thereof from ethyl acetate-hexane gave orange prism crystals. melting point: 66-67° C.

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