Potassium Iodide → methyl (3R,4R)-4-[3-(R,S)-hydroxy-3-(6-methoxyquinolin-4-yl)propyl]-1-[2-(cyclopentylthio)-ethyl]piperidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

0.717 g of methyl (3R,4R)-4-[3-(R,S)-hydroxy-3-(6-methoxyquinolin-4-yl)propyl]piperidine-3-carboxylate in 15 cm3 of acetonitrile and 15 cm3 of methanol was heated for 3½ h at a temperature in the region of the reflux temperature, with stirring and under an inert atmosphere, with 0.439 g of 90% 2-chloroethyl cyclopentyl sulfide in the presence of 0.332 g of potassium carbonate and 0.4 g of potassium iodide. After cooling the reaction mixture to a temperature in the region of 20° C., the insoluble material was filtered off and then washed with acetonitrile. The filtrate was evaporated under reduced pressure (5 kPa) at a temperature in the region of 40° C. The residue obtained was purified by chromatography under a nitrogen pressure of 100 kPa on a column of silica gel (particle size 40-63 μm; diameter 3.5 cm; height 45 cm), elution was carried out with a dichloromethane/methanol (95/5 by volume) mixture, and 35-cm3 fractions were collected. Fractions 25 to 45 were combined and then evaporated under reduced pressure (5 kPa) at a temperature in the region of 40° C. 0.48 g of methyl (3R,4R)-4-[3-(R,S)-hydroxy-3-(6-methoxyquinolin-4-yl)propyl]-1-[2-(cyclopentylthio)-ethyl]piperidine-3-carboxylate was obtained in the form of a lacquer with a dark-green color.

Provenance & Evidence