Hydrochloric Acid → (3R,4R)-4-[3-(R,S)-hydroxy-3-(6-methoxyquinolin-4-yl)propyl]-1-[2-(tert-butylthio)ethyl]piperidine-3-carboxylic acid dihydrochloride

Participants

Reaction Conditions

Reaction Steps

1 cm3 of 5N aqueous sodium hydroxide solution was added, with stirring and under an inert atmosphere, to a solution of 0.26 g of methyl (3R,4R)-4-[3-(R,S)-hydroxy-3-(6-methoxyquinolin-4-yl)propyl]-1-[2-(tert-butylthio)ethyl]piperidine-3-carboxylate in 5 cm3 of methanol. After heating the solution to a temperature in the region of 60° C. and then cooling to room temperature, the reaction mass was evaporated under reduced pressure (2.8 kPa) at a temperature in the region of 60° C. The residue obtained was taken up in 5 cm3 of distilled water and then 5 cm3 of concentrated hydrochloric acid (d=1.18) were added. The mixture was evaporated under reduced pressure (2.8 kPa) at a temperature in the region of 60° C. The residue obtained was taken up in 4 cm3 of a dichloromethane/methanol (90/10 by volume) mixture. The white precipitate obtained was filtered off and washed with 2 times 2 cm3 of this same mixture. The filtrate was concentrated under reduced pressure (2.8 kPa) at a temperature in the region of 40° C. The product obtained was dried under reduced pressure (16 Pa) at a temperature in the region of 60° C. 0.29 g of (3R,4R)-4-[3-(R,S)-hydroxy-3-(6-methoxyquinolin-4-yl)propyl]-1-[2-(tert-butylthio)ethyl]piperidine-3-carboxylic acid dihydrochloride was obtained in the form of a solid with a beige color melting with softening in the region of 169° C.

Provenance & Evidence