反应详情

Methanol (1 mL) was added to toluene (10 mL) under an argon atmosphere at room temperature. The flask was cooled in a water bath and 2M (trimethylsilyl)diazomethane (5 mL, 10 mmol) was added, followed by α-bromo-2-chlorophenyl acetic acid (2.2 g, 8.81 mmol) in portions over 5 minutes. After 10 additional minutes, the toluene/methanol was removed under reduced pressure. The crude oil was purified by MPLC (companion) on a silica cartridge (40 g) with a gradient of ethyl acetate in heptane (10% to 50%) over 20 minutes. The product containing fractions were combined, concentrated, and dried under high vacuum for 1 hour at room temperature to provide bromo-(2-chlorophenyl)-acetic acid methyl ester (2.0 g, 86% yield) as a clear liquid that solidified at low temperatures (−10° C.). 1H NMR (300 MHz, CDCl3/TMS): δ=7.75 (d, 11-1, J=6.9 Hz), 7.39-7.26 (m, 3H), 5.91 (s, 1H), 3.80 (s, 3H). 13C NMR (75 MHz, CDCl3/TMS): δ=168.29, 133.82, 133.30, 130.93, 130.47, 129.83, 127.66, 53, 80, 43.08.

1. temperatureThe flask was cooled in a water bath
2. customAfter 10 additional minutes, the toluene/methanol was removed under reduced pressure
3. customThe crude oil was purified by MPLC (companion) on a silica cartridge (40 g) with a gradient of ethyl acetate in heptane (10% to 50%) over 20 minutes
4. additionThe product containing fractions
5. concentrationconcentrated
6. customdried under high vacuum for 1 hour at room temperature