Lithium borohydride → (R)-Benzyl 2-((5-bromo-1H-indol-3-yl)methyl)pyrrolidine-1-carboxylate

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Reaction Steps

(R)-3-(N-Benzyloxycarbonylpyrrolidin-2-yl-carbonyl)-5-bromo-1H-indole (0.67 g, 1.57 mmol) was dissolved in anhydrous tetrahydrofuran (20 mL) and at room temperature under nitrogen was added lithium borohydride (2 molar in tetrahydrofuran) (1.2 mL, 2.4 mmol). The reaction mixture was stirred at room temperature for 3 hours and warmed to reflux for 16 hours. After cooling to room temperature, 2NHCl (10 mL) was added dropwise and the reaction mixture partitioned between ethyl acetate and water. The separated organic phase was washed with saturated aqueous sodium hydrogen carbonate (2×), brine (1×), dried (Na2SO4), and evaporated in vacuo to give a colourless oil. Purification by column chromatography on silica gel, eluting with dichloromethane gave the title compound as an oil (0.32 g). TLC (SiO2 :CH2Cl2): Rf =0.2.

Provenance & Evidence