Hydrochloric Acid → 1-Chloro-2-(2,4-difluorophenyl)butane-2,3-diol

Participants

Reaction Steps

To a solution of 0.45 g (1.28 mmol) of 1-chloro-2-(2,4-difluorophenyl)-3-(tert-butyldimethylsilyloxy)butan-2-ol ((2R,3S)/(2S,3S)=92/8) in 5 mL of methanol was added 0.25 mL of concentrated hydrochloric acid at room temperature. After the completion of the dropwise addition, stirring was performed at room temperature for 18 hours. Then, 10 mL of water was added to stop the reaction, and extraction was performed with ethyl acetate (20 mL). The resulting organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a crude product as a colorless oil. A quantitative analysis was performed by HPLC (under the same HPLC measurement conditions as those in Example 6). Thereby, the title compound was obtained in a yield of 75% ((2R,3S)/(2S,3S)=91/9). 1H-NMR (400 MHz, CDCl3) (2R,3S) δ: 0.98 (d, 3H, J=6.6 Hz), 2.48 (brs, 1H), 3.20 (s, 1H), 4.11-4.23 (m, 3H), 6.77-6.80 (m, 1H), 6.91-6.93 (m, 1H), 7.69-7.71 (m, 1H); (2S,3S) δ: 1.93 (dd, 3H, J=6.3, 1.2 Hz), 2.25 (d, 1H, J=5.2 Hz), 3.15 (s, 1H), 3.97 (d, J=11.0 Hz), 4.06 (q, 1H, J=6.3 Hz), 4.35 (d, J=11.2 Hz), 6.75-6.82 (m, 1H), 6.91-6.93 (m, 1H), 7.69-7.71 (m, 1H).

Provenance & Evidence