4-(2-Benzyloxyphenyl)-2,2-dimethyl-5-oxopiperazine-1-carboxylic acid t-butyl ester → 4-(2-Hydroxyphenyl)-2,2-dimethyl-5-oxopiperazine-1-carboxylic acid t-butyl ester

Participants

Reaction Steps

A suspension of 3.42 g of 4-(2-benzyloxyphenyl)-2,2-dimethyl-5-oxopiperazine-1-carboxylic acid t-butyl ester obtained in Example (10c) (8.94 mmol) and 342 mg of 10% palladium-carbon (50% wet) in methanol (90 ml) was stirred under a hydrogen atmosphere at room temperature for six hours. Hydrogen in the reaction vessel was replaced by nitrogen. Then, palladium-carbon was separated by filtration and washed with methanol. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (elution solvent:hexane/ethyl acetate=1/1) to obtain 2.6 g of the title compound (yield: quant.).

Provenance & Evidence