Iodine → 4-Fluoro-N-methyl-benzenebutanamine

Participants

Reaction Conditions

Reaction Steps

At 0° C., a solution of 4-(4-fluorophenyl)-N-methylbutyramide (1.30 g, 6.70 mmol) in THF (15 ml) was added dropwise to a suspension of sodium borohydride (604 mg, 16.0 mmol) in THF (15 ml). Successively, a solution of iodine (1.70 g, 6.70 mmol) in THF (20 ml) was added dropwise. The reaction mixture was heated to 70° C. for 16 hours. It was cooled to 0° C. Methanol (50 ml) was added carefully. The solvents were removed in vacuo. The residue was dissolved in a mixture of a 32% aqueous solution of sodium hydroxide (100 ml), water (50 ml), and tert-butyl methyl ether (200 ml). The phases were separated. The aqueous phase was extracted with tert-butyl methyl ether (2×100 ml). The combined organic layers were dried over magnesium sulphate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (80 g), using a mixture of DCM/methanol/25% aqueous ammonia (first 100:10:1, then 100:20:2) as eluent, to give 180 mg of N-[4-(4-fluorophenyl)butyl]-N-methylamine.

Provenance & Evidence