Carbon tetrabromide → 3-Bromo-pyrrolidine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

To a solution of (RS) 1-tert-butoxycarbonyl-3-pyrrolidinol (Prepn. 3) (3.00 g) in THF (90 mL), triphenylphosphine (12.4 g) was added, then a solution of CBr4 (15.7 g) in THF (90 mL) was dropped and the mixture stirred overnight at room temperature. The organic solvent was evaporated and the residue was extracted with EtOAc (4×50 mL). The combined organic extracts were washed with H2O, dried over Na2SO4 and evaporated to dryness. The residue was purified by flash chromatography (SiO2, cyclohexane/EtOAc 80/20) to give (RS) 1-tert-butoxycarbonyl-3-bromopyrrolidine in 80% yield as yellow oil. 1H-NMR (300 MHz, DMSO-d6, ppm from TMS): δ 4.85 (1H, m), 3.70-3.59 (1H, m), 3.55-2.10 (5H, m), 1.35 (9H, s).

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