反应详情

To a solution of 5-nitro-2-thiophenecarboxylic acid (20 g, 0.11 mol) in DMF (140 ml) were added sequentially allyl bromide (40 ml, 0.46 mol) and triethylamine (64 ml, 0.46 mol) with cooling to maintain the temperature of the reaction mixture below 30° C. After addition of the reagents, the reaction mixture was stirred for 3 hours at ambient temperature and then diluted with ethyl acetate. The solid which precipitated was filtered off, the filtrate washed with water, washed with saturated aqueous solution of sodium chloride, dried over MgSO4 and concentrated. The residue was purified by chromatography on silica gel using a mixture of CH2Cl2 --petroleum ether (3:7) as eluent to give the title compound as a white solid (8.8 g, 38%).

1. temperaturewith cooling
2. temperatureto maintain the temperature of the reaction mixture below 30° C
3. additionAfter addition of the reagents
4. customThe solid which precipitated
5. filtrationwas filtered off
6. washthe filtrate washed with water
7. washwashed with saturated aqueous solution of sodium chloride
8. dry with materialdried over MgSO4
9. concentrationconcentrated
10. customThe residue was purified by chromatography on silica gel using
11. additiona mixture of CH2Cl2 --petroleum ether (3:7) as eluent