3-Chloro-2-butanone → 4,5-Dimethyl-2-(4-nitrobenzyl)-1,3-thiazole

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Reaction Steps

A mixture of 2-(4-nitrophenyl)ethanethioamide (1.11 g), 2-chloro-3-butanone (0.75 g) and tert-butanol (50 ml) was heated under reflux for 4 days. The reaction mixture was concentrated, and water and saturated aqueous sodium hydrogen carbonate were added to the residue. The mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography to give 4,5-dimethyl-2-(4-nitrobenzyl)-1,3-thiazole as pale-yellow crystals (0.67 g, yield 47%) from a fraction eluted with hexane-ethyl acetate (2:1-1:1, v/v). Recrystallization thereof from ethyl acetate-hexane gave pale-yellow prism crystals. melting point: 93-94° C.

Provenance & Evidence