Hydrochloric Acid → 4-[3-(3-Chloro-6-methoxyquinolin-4-yl)propyl]-1-[2-(cyclopentylthio)ethyl]piperidine-4-carboxylic acid dihydrochloride

Participants

Reaction Conditions

Reaction Steps

A mixture of 0.55 g of ethyl 4-[3-(3-chloro-6-methoxyquinolin-4-yl)propyl]-1-[2-(cyclopentylthio)ethyl]-piperidine-4-carboxylate in 8 cm3 of aqueous 6 N hydrochloric acid was heated at a temperature in the region of 100° C., with stirring and under an inert atmosphere, for 5 hours. After stirring for 18 hours at a temperature in the region of 20° C., the solution obtained was concentrated under reduced pressure (5 kPa) at a temperature in the region of 40° C. The evaporation residue obtained was taken up in 10 cm3 of a mixture of dichloromethane/methanol (90/10 by volume) and then concentrated under the same conditions as above. 0.59 g of 4-[3-(3-chloro-6-methoxyquinolin-4-yl)propyl]-1-[2-(cyclopentylthio)ethyl]piperidine-4-carboxylic acid dihydrochloride was obtained in the form of a foam melting at 129° C. with softening.

Provenance & Evidence