[BH4-].[Na+].[Te].Br[C:5]1(Br)[CH2:9][CH:8]([C:10]2[CH:11]=[N:12][CH:13]=[C:14]([Br:16])[CH:15]=2)[NH:7][C:6]1=[O:17]>C(O)C>[Br:16][C:14]1[CH:15]=[C:10]([CH:8]2[NH:7][C:6](=[O:17])[CH2:5][CH2:9]2)[CH:11]=[N:12][CH:13]=1Sodium borohydride (0.74 g, 19.6 mmol) is suspended in ethanol (17 mL) and tellurium metal powder (1.25 g, 9.78 mmol) is added in portions. The mixture is heated under reflux (external temperature 80° C.) for 15 min and the mixture becomes a light purple color. The mixture is cooled to room temperature. 3,3-Dibromo-5-(5-bromo-pyridin-3-yl)-pyrrolidin-2-one (0.65 g, 1.63 mmol) dissolved in EOH (5 mL) is added slowly. The mixture is stirred at room temperature over the weekend (72 h). The mixture is filtered through diatomaceous earth and washed with MeOH. The filtrate is concentrated. The resulting crude product is purified by normal phase chromatography using 0-6% MeOH in DCM as the gradient to afford 5-(5-bromo-pyridin-3-yl)-pyrrolidin-2-one (291 mg, 74% yield).
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