Hydrochloric Acid → 3-(Dimethylamino)-1-(3,4,5-trimethoxyphenyl)propan-1-one

Participants

Reaction Conditions

Reaction Steps

Concentrated hydrochloric acid (1 mL) was added to a stirred mixture of 3,4,5-trimethoxyacetophenone (210 g, 1 mole), dimethylamine hydrochloride (81 g, 1 mole) and paraformaldehyde (45 g, 1.5 mole) in ethanol (300 mL). The reaction mixture was heated under reflux for 1 hour. Another portion of paraformaldehyde (30 g, 1 mole) was added, and the heating was continued for another 2 hours. The warm reaction mixture was poured with vigorous stirring into acetone (2.4 L). The slurry was heated at 60° C. for 15 minutes, cooled, and filtered. The solid was washed with acetone and dried to provide the hydrochloride salt of 3-(N,N-dimethylamino)-1-(3,4,5-trimethoxyphenyl)propan-1-one, R, 0.05 (SiO2, 2:1 [v/v] hexane-ethyl acetate); m.p. 175° C. A mixture of the above hydrochloride (147.5 g, 0.48 mole) in 1 N NaOH (750 mL) was shaken with ethyl acetate (4×100 mL). The combined organic extracts were washed with brine, dried, and evaporated in vacuo to provide 3-(N,N-dimethylamino)-1-(3,4,5-trimethoxyphenyl)propan-1-one.

Provenance & Evidence