Ammonium Acetate → Ethyl 4-amino-3-methylpiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Ammonium acetate (5 g, 64.93 mmol) was added to the stirred solution of 1-carbethoxy-3-methyl-4-piperidone (1.4 g, 7.56 mmol) in methanol (25 ml) and stirring was continued for 3 hr at ambient temperature. The resulting mixture was cooled at 0° C. and sodium cyanoborohydride (0.5 g, 7.93 mmol) was added to it. Cooling was removed after 10 min. and resulting mixture was stirred for 6 hr at ambient temperature. The reaction mixture was concentrated to dryness, triturated with water, acidified with conc. HCl (pH 3˜4) and extracted with ethyl acetate to remove impurities. The aqueous layer was basified with 1 M sodium hydroxide solution (pH˜10) and extracted with ethyl acetate. Ethyl acetate extract was dried (Na2SO4) and concentrated to dryness to furnish 4-amino-1-carbethoxy-3-methylpiperidine. Yield 1.0 g (72%), C9H18N2O2, m/z 187 (M+1), PMR (CDCl3): 0.94 (dd, 3H), 1.22 (m, 1H), 1.26 (t, 3H), 1.6 (m, 1H), 1.82 (m, 1H), 2.4 (m, 1H), 2.82 (m, 1H), 3.34 (m, 2H), 3.64 (m, 1H) 4.14 (q, 2H).

Provenance & Evidence