1,5-Dibromopentane → methyl(S)-3-tert-butoxycarbonylamino-2-piperidin-1-ylpropanoate

Participants

Reaction Conditions

Reaction Steps

14.4 ml (104 mmol) of triethylamine are added to a solution of 8.0 g (31 mmol) of commercial methyl (S)-2-amino-3-tert-butoxycarbonylaminopropanoate hydrochloride in 160 ml of tert-butanol, and then the reaction medium is stirred for 30 min at 40° C., and filtered in order to remove the triethylammonium salts. 6 ml (44 mmol) of 1,5-dibromopentane are added to the filtrate thus obtained, and the reaction medium is heated at 80° C. for 3 days. After the insoluble material has been filtered off, the filtrate is concentrated under vacuum. The crude residue is purified by chromatography on silica gel, elution being carried out with a 70/30 heptane/ethyl acetate mixture. 5.3 g (59%) of methyl(S)-3-tert-butoxycarbonylamino-2-piperidin-1-ylpropanoate are obtained in the form of a colorless oil.

Provenance & Evidence