Triethylamine → tert-Butyl 4-(2-{[tert-butyldiphenylsilyl]oxy}ethyl)-4-hydroxy-1-piperidine-carboxylate

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Reaction Conditions

Reaction Steps

A solution of 21.50 ml (82.50 mmol) of tert-butyldiphenylsilyl chloride in 15 ml of dichloromethane is added dropwise, under an inert atmosphere, to a solution of 18.4 g (75 mmol) of tert-butyl 4-hydroxy-4-(2-hydroxyethyl)-1-piperidinecarboxylate, obtained in step 12.1, and 11.60 ml (82.50 mmol) of triethylamine in 100 ml of dichloromethane, cooled to about 0° C. The mixture is allowed to warm to room temperature and stifling is then continued for 12 hours. Saturated aqueous ammonium chloride solution is added to the reaction medium. The aqueous phase is separated out and extracted twice with dichloromethane, the combined organic phases are washed with saturated aqueous sodium chloride solution and dried over sodium sulfate, and the filtrate is concentrated under reduced pressure. The residue thus obtained is purified by chromatography on silica gel, eluting with a 10/90 and then 20/80 mixture of ethyl acetate and cyclohexane.

Provenance & Evidence