Dichloromethane → Benzeneacetic acid, 2,6-difluoro-4-hydroxy-, methyl ester
Reaktionsgleichung
[F:1][C:2]1[CH:7]=[C:6]([O:8]C)[CH:5]=[C:4]([F:10])[C:3]=1[CH2:11][C:12]([OH:14])=[O:13].B(Br)(Br)Br.Cl[CH2:20]Cl>>[F:1][C:2]1[CH:7]=[C:6]([OH:8])[CH:5]=[C:4]([F:10])[C:3]=1[CH2:11][C:12]([O:14][CH3:20])=[O:13]Komponenten
4
Versuchsvorschrift
To a stirred solution of (2,6-difluoro-4-methoxyphenyl)acetic acid (1.50 g, 7.42 mmol) in 20 ml anhydrous dichloromethane at 0° C. was added a solution of boron tribromide (4.29 ml, 44.5 mmol) in 10 ml anhydrous dichloromethane. The cooling bath was removed and the mixture allowed to warm to RT for 2 hours. The reaction was diluted with 20 ml anhydrous methanol, and stirred for 30 minutes. The mixture was concentrated under reduced pressure, and the residue purified by column chromatography on silica gel, (Biotage column, 50 g) using a gradient eluent of 0-30% ethyl acetate in hexanes (700 ml) to afford the title compound. 1H NMR (CDCl3): δ 6.30 (d, J=8.3 Hz, 2H), 6.12 (br, 1H), 3.76 (s, 3H), 3.63 (s, 2H).