反应详情

Concentrated sulfuric acid (1.75 g, 17.8 mmol) was added drop wise to a cooled (ice bath) mixture of 4-bromo-5-methyl-phenol (Compound 45, 10 g, 53.46 mmol) and 3-chloro-2-methyl-propene (5.28 mL, 53.46 mmol). The dark reaction mixture was allowed to warm to ambient temperature and stirred a total of 2 hours. The reaction mixture was diluted with water, and extracted with diethylether. The combined organic extract was washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated to an oil. Flash column chromatography using 3% ethyl acetate in hexanes as the eluent afforded the title compound (6.2 g, 48%) as a green solid; 4-bromo-5-methyl-phenol was recovered. 1H NMR (300 MHz, CDCl3): δ 7.35 (s, 1H), 6.54 (s, 1H), 5.02 (s, 1H), 3.96 (s, 2H), 2.28 (s, 3H), 1.44 (s, 6H).

1. temperaturea cooled
2. customThe dark reaction mixture
3. extractionextracted with diethylether
4. extractionThe combined organic extract
5. washwas washed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. customevaporated to an oil