Dimethylformamide → (2,5-Difluoro-4-methylphenyl)methanol

関与物質

反応条件

反応手順

A mixture of 1-bromo-2,5-difluoro-4-methyl-benzene (3.3 g, 16 mmol) and ether (75 mL) was cooled to −78° C., and a solution of n-butyllithium in hexane (5.4 mL, 2.5 M, 13.5 mmol) was added dropwise. After stirring for 1 hour, dimethylformamide (1.1 mL, 14 mmol) was added, and the mixture was stirred for 1 hour. The mixture was treated with 1M HCl and water, warmed to ambient temperature and was extracted 3× with ether. The combined organic layers were dried over MgSO4, filtered and concentrated in vacuo. The residue was diluted with tetrahydrofuran (50 mL), and the mixture was treated with sodium borohydride (0.50 g, 13.5 mmol) and ethanol (2 mL). After stirring for 30 minutes, the mixture was diluted cautiously with 0.5M aqueous HCl, extracted 3× with ethyl acetate, and the combined organic layers were dried over Na2SO4, filtered and concentrated in vacuo. Recrystallization of the residue from hexane afforded 1.24 g (54%) of (2,5-difluoro-4-methyl-phenyl)-methanol as a colorless solid. 1H NMR (400 MHz, CDCl3) δ7.05 (dd, 1H, J=6.0, 9.2 Hz), 6.84 (dd, 1H, J=6.4, 10 Hz), 4.68 (d, 2H, J=6.0 Hz), 2.23 (s, 3H), 1.76 (t, 1H, J=6.0 Hz) ppm.

情報源と証拠