반응 #166193

반응 방정식

TBME

2,3-difluoro-4-methyl-benzoic acid tert-butyl ester

N-bromosuccinimide

AIBN

→

title compound

수율 71.6%

4-Bromomethyl-2,3-difluoro-benzoic acid tert-butyl ester

수율 71.6%

용매

carbon tetrachloride

cyclohexane

반응 조건

후처리

1. 1
   온도at reflux for 18 hours
2. 2
   여과filtered
3. 3
   농축The filtrate was concentrated in vacuo
4. 4
   기타to give a residue which

실험 절차

A solution of 2,3-difluoro-4-methyl-benzoic acid tert-butyl ester (17.3 g, 75.9 mmol) and N-bromosuccinimide (13.5 g, 75.9 mmol) in carbon tetrachloride (250 mL) was degassed for 10 minutes. AIBN (1.2 g, 7.32 mmol) was added and the reaction mixture was stirred at reflux for 18 hours before being cooled to room temperature and filtered. The filtrate was concentrated in vacuo to give a residue which was subjected to flash chromatography (Si—PPC, gradient 0% to 10%, TBME in cyclohexane) to afford the title compound as a colourless oil (16.7 g, contaminated by 25% of starting material). 1H NMR (CDCl3, 400 MHz) 7.61 (1 H, ddd, J=8.3, 6.4, 2.1 Hz), 7.18 (1 H, ddd, J=8.1, 6.4, 1.8 Hz), 4.49 (2 H, d, J=1.3 Hz), 1.59 (9 H, s).

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