Water → 4-Amino-4-(4-chlorophenyl)butan-1-ol

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Reaction Steps

4-(4-Chlorophenyl)-4-(methoxyimino)butanoic acid (Intermediate 53) (6.43 g, 26.61 mmol) in tetrahydrofuran (30 mL) was cooled, under an atmosphere of nitrogen, in an ice-methanol bath. Borane-tetrahydrofuran complex (1.0M in THF) (93 mL, 93.12 mmol) was added dropwise over a period of 20 minutes. The resulting solution was allowed to warm to room temperature, stirred for 1 hour then heated at reflux for a further 6 hours. After cooling in ice-water the mixture was treated with water (20 mL) dropwise with stirring over 10 minutes. The mixture was again allowed to warm to room temperature and stirred for 2 hours before evaporating the bulk of the solvent. The residue was then cooled in ice-water and 50% NaOH (aq.) (20 mL) added dropwise with stirring. The resulting mixture was stirred and heated at 90° C. for 4 hours then cooled to room temperature and extracted three times with Et2O. The combined extracts were washed with water followed by brine, dried over MgSO4 and evaporated to dryness. The crude product was then purified by flash silica chromatography (eluent 0-10% 7N ammonia in MeOH/DCM) and pure fractions evaporated to afford 4-amino-4-(4-chlorophenyl)butan-1-ol (3.88 g, 73.0%) as a colourless, transparent gum.

Provenance & Evidence