反应详情

A solution of ethyl 4-(3-bromophenyl)-3-methylbut-2-enoate (8.07 g, 28.5 mmol) in concentrated sulfuric acid (20 mL) was stirred at 60° C. for 90 minutes. The reaction mixture was poured onto ice and diluted with water and extracted with ethyl acetate. The organic layer was concentrated and purified by flash column chromatography (silica gel, ethyl acetate/hexanes) to give the desired compound. 1H-NMR: 400 MHz, (CDCl3) δ: 7.98 (d, J=10.4 Hz, 1H), 7.83 (s, 1H), 7.43 (d, J=7.2 Hz, 1H), 7.08 (s, 1H), 6.67 (s, 1H), 2.42 (s, 3H). LCMS-ESI− (m/z): [M−H]− calcd for C11H9BrO: 236.09. Found: 236.9.

1. additionThe reaction mixture was poured onto ice
2. extractionextracted with ethyl acetate
3. concentrationThe organic layer was concentrated
4. custompurified by flash column chromatography (silica gel, ethyl acetate/hexanes)