Sodium borohydride → (R)-tert-butyl 3-((3-chloro-2-fluorophenyl)(2-hydroxyethoxy)methyl)piperidine-1-carboxylate

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Reaction Steps

To a solution of (R)-tert-butyl 3-((3-chloro-2-fluorophenyl)(2-ethoxy-2-oxoethoxy)-methyl)piperidine-1-carboxylate (4.368 g, 10.2 mmol) in MeOH (85 mL) was added NaBH4 (3.18 g, 81.5 mmol) in portions such that the temperature remained below 40° C. After addition, the mixture was stirred at rt for 2˜3 h. TLC showed the starting material had disappeared. The solvent was removed in vaczio and the residue was partitioned between water and EtOAc. The organic layer was washed with H2O and brine, dried over Na2SO4 and evaporated to give (R)-tert-butyl 3-((3-chloro-2-fluorophenyl)(2-hydroxyethoxy)methyl)piperidine-1-carboxylate (3.5 g, 89%). 1H NMR (400 MHz, CDCl3): 1.18 (m, 1H), 1.38-1.46 (s, 9H), 1.65 (m, 1H), 1.85 (m, 2H), 2.66 (m, 1H), 3.25 (m, 1H), 3.38 (m, 2H), 3.69 (m, 3H), 3.93 (m, 1H), 4.52 (m, 6H); MS (E/Z): 388 (M+1)

Provenance & Evidence