反应详情

温度

0 °C

Formation of the amide bond was carried out using an adaptation of General Method A, above. A mixture of commercially available (2S,4R)-tert-butyl 4-hydroxy-2-(hydroxymethyl)pyrrolidine-1-carboxylate (3.26 g, 15 mmol) in 50 mL of DCM/TFA (3:2, v/v) was stirred at rt for 4 h, concentrated in vacuo to give a brown oil as a crude TFA salt of (3R,5S)-5-(hydroxymethyl)pyrrolidin-3-ol, which was dissolved in DMF (28 mL), added with biphenyl-2-carboxylic acid (3.05 g, 15.4 mmol) and HATU (5.86 g, 15.4 mmol). The resulting solution was cooled to 0° C., added with Et3N (8.8 mL, 63 mmol) dropwise and was allowed to warm to rt gradually and stirred overnight. 2M NaOH (aq.) was added and the mixture was extracted with EtOAc (3×). The combined EtOAc solution was washed with brine, dried over MgSO4 and concentrated in vacuo to a brown oil, which was purified by column chromatography on silica gel (10% MeOH in EtOAc) to provide biphenyl-2-yl((2S,4R)-4-hydroxy-2-(hydroxymethyl)pyrrolidin-1-yl)methanone as an off-white solid (2.0 g, 45% yield over two steps). 1H NMR (CDCl3, 400 MHz) δ 7.59-7.57 (m, 2H), 7.54-7.40 (m, 7H), 4.44 (brs, 1H), 4.10 (s, 1H), 3.77-3.72 (m, 1H), 3.62 (brs, 1H), 3.32 (brs, 1H), 3.04-2.96 (m, 1H), 2.60 (brs, 1H), 2.00-1.95 (m, 1H), 1.61 (brs, 2H). MS (ESI) 298.04 (M+H).

1. temperatureto warm to rt gradually
2. extractionthe mixture was extracted with EtOAc (3×)
3. washThe combined EtOAc solution was washed with brine
4. dry with materialdried over MgSO4
5. concentrationconcentrated in vacuo to a brown oil, which
6. customwas purified by column chromatography on silica gel (10% MeOH in EtOAc)