反应详情

2-[2-(4-Trifluoromethyl-phenyl)-vinyl]-oxazole-4-carboxylic acid ethyl ester (1.64 g, 5.2 mmol) is dissolved in THF (20 ml), treated with aq. NaOH (1N, 10.5 ml, 10.5 mmol) and stirred for 1 h at reflux temperature. After cooling water is added and the mixture acidified with aq. HCl (3N). The mixture is extracted with ethyl acetate (3×50 ml), the extract washed with brine (50 ml), dried over sodium sulfate and concentrated in vacuo yielding 2-[2-(4-trifluoromethyl-phenyl)-vinyl]-oxazole-4-carboxylic acid as a colorless solid. Yield 1.36 g (92%)

1. temperatureat reflux temperature
2. additionis added
3. extractionThe mixture is extracted with ethyl acetate (3×50 ml)
4. washthe extract washed with brine (50 ml)
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated in vacuo