Reaktion #48214

Reaktionsgleichung

benzoic acid 2-fluoro-5-methyl-phenyl ester

N-bromo-succinimide

dibenzoylperoxide

water

→

Benzoic Acid 5-bromomethyl-2-fluoro-phenyl Ester

Lösungsmittel

carbon tetrachloride

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturto reflux for 2 h (TLC monitored)
3. 3
   SonstigeThe organic layer was separated
4. 4
   Waschenwashed with brine (20 mL)
5. 5
   Trocknendried over sodium sulphate
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   SonstigeThe residue was purified by column chromatography (EtOAc:hexane, 1:25, Rf: 0.28)

Vorschrift

A mixture of benzoic acid 2-fluoro-5-methyl-phenyl ester (CAB02145, 2.47 g, 10.0 mmol), N-bromo-succinimide (1.96 g, 11.0 mmol) and dibenzoylperoxide (10 mg) in carbon tetrachloride (25 mL) was heated to reflux for 2 h (TLC monitored). After cooling to room temperature, water (50 mL) and diethyl ether (100 mL) were added. The organic layer was separated, washed with brine (20 mL), dried over sodium sulphate and concentrated under reduced pressure. The residue was purified by column chromatography (EtOAc:hexane, 1:25, Rf: 0.28). Yield: 1.80 g (58%), white solid. 1H-NMR (400 MHz, CDCl3) δ=4.48 (s, 2H, —CH2Br), 7.18 (dd, J=9.8, 8.6 Hz, 1H), 7.28 (ddd, J=8.6, 4.3, 2.3 Hz, 1H), 7.34 (dd, J=7.0, 2.3 Hz, 1H), 7.50-7.55 (m, 2H), 7.64-7.69 (m, 1H), 8.18-8.23 (m, 2H). LRMS (FAB+): 229.1 (95), 309.0 (100, [M+]+). Found: C, 54.1, H, 3.22%; C14H10BrFO2 (309.13) requires C, 54.39, H, 3.26%.

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