Methyl iodide → 4-[(2-Bromo-phenyl)-methyl-amino]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 4-(2-bromophenylamino)-piperidine-1-carboxylic acid tert-butyl ester (2.0 g, 0.00562 mole), in DMF (10 mL) was added NaH (60% w/w dispersion in oil) (0.9 g, 0.02251 mole) and the resulting mixture was stirred at ambient temperature for 10 minutes under an atmosphere of nitrogen. Methyl iodide (3.19 g, 0.0225 mole) was then added and stirring was continued for 30 minutes at ambient temperature. The reaction mixture was quenched with aqueous NH4Cl solution and the product was extracted with ether. The ether layer with washed with aqueous NaHCO3 solution followed by brine solution. The ether layer collected was dried over sodium sulfate and concentrated under reduced pressure. The resulting residue was washed with ether and dried to afford 0.893 g (45%) of 4-[(2-bromo-phenyl)-methyl-amino]-piperidine-1-carboxylic acid tert-butyl ester. 1H NMR (CDCl3): δ 7.6-7.54 (m, 1H), 7.28-7.2 (m, 1H), 7.14-7.08 (m, 1H), 6.96-6.88 (m, 1H), 4.2-4.0 (m, 2H), 3.3-3.2 (m, 1H), 2.8-2.7 (m, 2H), 2.7 (s, 3H), 1.7-1.6 (m, 2H), 1.6 (m, 1H), 1.45 (s, 9H). A solution of 4-[(2-bromo-phenyl)-methyl-amino]-piperidine-1-carboxylic acid tert-butyl ester (0.89 g, 0.0024 mole) in dioxane.HCl was stirred for 30 minutes. The reaction was concentrated under reduced pressure to afford 0.704 g (95%) of (2-bromo-phenyl)-methyl-piperidin-4-yl-amine. 1H NMR (DMSO-d6): δ 9.0 (bd, 3H), 7.6 (m, 1H), 7.4 (m, 2H), 7.0 (m, 1H), 3.2 (m, 3H), 2.9 (m, 2H), 2.6 (s, 3H), 1.9 (m, 3H).

Provenance & Evidence