反应详情

温度

130 °C

A mixture of methyl 4-carbamoylbenzoate (896 mg), 2-trifluoromethylphenacyl bromide (2.22 g) and N,N-dimethylformamide (5 ml) was stirred at 130° C. for 2 hours. Hot ethanol was added to the reaction mixture, which was poured into water, and extracted with ethyl acetate. The ethyl acetate layer was concentrated, and the residue was subjected to a silica gel column chromatography to obtain methyl 4-[4-(2-trifluoromethylphenyl)-2-oxazolyl]benzoate as an oil from a fraction eluted with ethyl acetate-hexane. This oil was dissolved in a mixture of tetrahydrofuran (10 ml) and ethanol (10 ml), and hydrolyzed by adding a 1N aqueous solution of sodium hydroxide (10 ml). The reaction mixture was neutralized with 1N hydrochloric acid, and precipitated crystals were collected by filtration. The product was recrystallized from acetone-hexane to obtain 4-[4-(2-trifluoromethylphenyl)-2-oxazolyl]benzoic acid (203 mg, yield: 12%). Colorless prisms. Melting Point: 264 to 265° C.

1. extractionextracted with ethyl acetate
2. concentrationThe ethyl acetate layer was concentrated