Hydrochloric Acid → Ethyl 4-{4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-oxobutyl}-alpha,alpha-dimethylbenzeneacetate hydrochloride

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Reaction Steps

Dissolve 2-[4-(4-chloro-butyryl)-phenyl]-2-methyl-propionic acid, ethyl ester (15.0 g, 49.53 mmol) and α,α-diphenyl-4-piperidinemethanol (29.66 g, 106.4 mmol) in xylene (60 mL). Reflux for 5.5 hours, cool in an ice bath, filter and wash with cold xylenes (25 mL). Filter the filtrate though silica gel (20 g) and wash the gel with xylenes (40 mL). Add xylene (60 mL) and concentrated hydrochloric acid (6.45 g, 65.6 mmol) with stirring. Add additional xylenes (40 mL) and stir for 2 hour. Filter, wash with xylene (50 mL), vacuum dry and slurry with a mixture of ethanol (60 mL) and hexane (120 mL) at 70-72° C. for 30 minutes. Filter, wash with 3:1 v/v solution of n-heptane/ethanol (30 mL) and dry to give the title compound as a light white solid (19.7 g, 70%); mp 206-208° C.

Provenance & Evidence