Hydrochloric Acid → HCID 59865002, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of crude 1,1-dimethylethyl-4-(4-{[3-(3,3-dimethyl-1-piperidinyl)propyl]oxy}phenyl)-4-hydroxy-1-piperidinecarboxylate (100 g) in 95% ethanol (500 ml) is cooled to 5-10° C. and concentrated hydrogen chloride (300 ml) is added at 5-10° C. over about 45 min, then stirred for about 15 min. The mixture is then heated to reflux (about 80-85° C.) for about 6 h. The mixture is concentrated under vacuum at 50-60° C., then water (500 ml) is added. The mixture is then cooled to 5-10° C. and the pH adjusted to pH 10-12 with 2N sodium hydroxide solution at 5-10° C. The mixture is warmed to 25-35° C., and extracted with ethyl acetate (500 ml, then 2×200 ml). The combined ethyl acetate layers are washed with water (200 ml), then 10% aqueous sodium chloride solution (200 ml). The solvent is removed under vacuum and the product is purified by column chromatography (100-200 mesh silica gels) using a linear gradient of MeOH/DCM 0-70% to give the title compound (21.7 g).

Provenance & Evidence