反应详情

A suspension of methyl 3-cyano-2-methylbenzoate (10.6 g, 60.5 mmol), NBS (16.2 g, 90.7 mmol) and azobisisobutyronitrile (AIBN) (100 mg) in tetrachloromethane (200 mL) was refluxed under nitrogen atmosphere for 6 hours. Alternatively, the bromination step was carried out using NBS in benzene, using benzoyl peroxide as a catalyst. TLC analysis showed the complete consumption of methyl 3-cyano-2-methylbenzoate (TLC solvent: 10% ethyl acetate in hexane). The reaction mixture was filtered and washed with chloroform (3×20 mL). The combined filtrate and washings were concentrated under reduced pressure. The residue was washed through a short column of silica gel using 10% ethyl acetate in hexanes as an eluent. The eluent was concentrated and the resultant product dried under vacuum overnight to provide 15.1 g of methyl 2-bromomethyl-3-cyanobenzoate (98% yield). 1H NMR spectrum (in DMSO-d6): δ 8.15, (d, J=8.0 Hz, 1H); 8.12 (d, J=7.9 Hz, 1H); 7.67 (t, 1H); 5.04 (s, 2H); 3.89 (s, 3H).

1. temperaturewas refluxed under nitrogen atmosphere for 6 hours
2. customthe complete consumption of methyl 3-cyano-2-methylbenzoate (TLC solvent: 10% ethyl acetate in hexane)
3. filtrationThe reaction mixture was filtered
4. washwashed with chloroform (3×20 mL)
5. concentrationThe combined filtrate and washings were concentrated under reduced pressure
6. washThe residue was washed through a short column of silica gel using 10% ethyl acetate in hexanes as an eluent
7. concentrationThe eluent was concentrated
8. dry with materialthe resultant product dried under vacuum overnight