反应详情

A mixture of 3-chloro-4-hydroxy benzoic acid methyl ester (4.665 g, 25 mmol), benzyl bromide (5.13 g, 30 mmol) and potassium carbonate (6.91 g, 50 mmol) in N,N-dimethylformamide (50 mL) was stirred overnight at room temperature. The reaction mixture was poured onto crushed ice (ca. 300 g) and the product was extracted with ethyl acetate (2×100 mL). The combined organic layers were dried over sodium sulphate and concentrated under reduced pressure. The residue was dissolved in dichloromethane and precipitated by addition of hexane. Yield: 6.47 g (94%) white powder. 1H-NMR (400 MHz, CDCl3) δ=3.90 (s, 3H, —OCH3); 5.23 (s, 2H, —CH2Ar), 6.99 (d, J=9.0 Hz, 1H), 7.31-7.48 (m, 5H), 7.89 (dd, J=9.0, 2.3 Hz, 1H), 8.08 (d, J=2.3 Hz, 1H).

1. additionThe reaction mixture was poured
2. extractionthe product was extracted with ethyl acetate (2×100 mL)
3. dry with materialThe combined organic layers were dried over sodium sulphate
4. concentrationconcentrated under reduced pressure
5. dissolutionThe residue was dissolved in dichloromethane
6. customprecipitated by addition of hexane