Acetic Acid → 1-Carbethoxy-4-dimethylamino-3-methylpiperidine

Participants

Reaction Steps

Paraformaldehyde (5.1 g) was added to the stirred solution of 4-amino-1-carbethoxy-3-methylpiperidine (3.5 g, 18.8 mmol) in methanol (100 ml) at 0° C. and sodium cyanoborohydride (1.7 g, 27.0 mmol) was added to it. Then, acetic acid (1 ml) was added to the resulting mixture and stirring was continued for 96 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 give 1-carbethoxy-4-dimethylamino-3-methylpiperidine. Yield 3.5 g (88%), C11H22N2O2, m/z 215 (M+1).

Provenance & Evidence