反应详情

A mixture of methyl 3-methyl-2-thienylketone (14 g., 0.10 mole), N-bromosuccinimide (18 g., 0.10 mole), α,α-azobisisobutyronitrile (AIBN, 0.3 g.), and carbon tetrachloride (300 ml.) was heated cautiously to reflux under a nitrogen atmosphere. After stirring 4 hours at reflux, the mixture was cooled, filtered to remove succinimide, washed first with sodium bicarbonate solution, then with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was evaporated at reduced pressure to obtain a pale yellow solid which was recrystallized from hexane to obtain 16 g. (73%) of the desired product as colorless crystals, M.P. 62°-64° C. 1H--NMR (CDCl3), ppm. (δ): 7.5 (d, J=5, aromatic-H), 7.2 (d, J=5, aromatic-H), 4.9 (s, CH2Br) and 2.55 (s, CH3). This compound is a strong irritant.

1. temperaturewas heated cautiously
2. temperatureto reflux under a nitrogen atmosphere
3. temperatureat reflux
4. temperaturethe mixture was cooled
5. filtrationfiltered
6. customto remove succinimide
7. washwashed first with sodium bicarbonate solution
8. dry with materialwith saturated sodium chloride solution and dried over anhydrous magnesium sulfate
9. customThe solvent was evaporated at reduced pressure
10. customto obtain a pale yellow solid which
11. customwas recrystallized from hexane
12. customto obtain 16 g