Imidazole → 5-[3-Bromo-3-(tert-butyl-dimethyl-silanyloxy)-butyl]-pyrrolidin-2-one

Participants

Reaction Steps

To a solution of 5-(3-bromo-3-hydroxy-butyl)-pyrrolidin-2-one (6.76 g, 21.6 mmol) in DMF (86 mL) was added tert-butyldimethylsilyl chloride (3.59 g, 23.8 mmol) followed by imidazole (2.95 g, 43.3 mmol) and DMAP (264 mg, 2.16 mmol). The reaction was stirred for 24 h and was quenched with saturated aqueous ammonium chloride. The aqueous solution was washed with EtOAc (3×) and the combined organic extracts were dried (MgSO4), filtered, and concentrated. Purification by medium pressure chromatography using a solvent gradient (CH2Cl2 to 1% MeOH in CH2Cl2 to 3% MeOH in CH2Cl2 to 5% MeOH in CH2Cl2 to 8% MeOH in CH2Cl2) provided 5-[3-bromo-3-(tert-butyl-dimethyl-silanyloxy)-butyl]-pyrrolidin-2-one (7.45 g). 1H NMR (CDCl3) δ7.30 (m, 2H), 7.12 (m, 1H), 7.04 (m, 1H), 5.71 (m, 1H), 3.81 (m, 1), 3.56 (m, 1H), 2.66 (m, 2H), 2.32-2.17 (m, 3H), 1.70-1.35 (m, 5H), 0.82 (s, 9H), −0.06 (d, 3H), −0.24 (d, 3H); MS 426.2, 428.2 (M+).

Provenance & Evidence