1-Bromo-2,3,5-trifluorobenzene → (3R,4R)-methyl 4-(3-(6-methoxyquinolin-4-yl)-3-oxopropyl)-1-(3-(2,3,5-trifluorophenyl)prop-2-ynyl)piperidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

4.05 g of tetrakis(triphenylphosphine)palladium, 0.834 g of cuprous iodide and 7.9 cm3 of 1-bromo-2,3,5-trifluorobenzene are added at a temperature in the region of 20° C., with stirring and under an inert atmosphere, to a solution of 17.28 g of methyl (3R,4R)-1-(3-prop-2-ynyl)-4-[3-oxo-3-(6-methoxyquinolin-4-yl)propyl]piperidine-3-carboxylate in 173 cm3 of triethylamine. After heating for 2 hours at a temperature in the region of 80° C., the reaction mixture is cooled to approximately 20° C., diluted with 100 cm3 of water and then extracted with 4 times 150 cm3 of ethyl acetate. The organic extracts are combined, washed with 5 times 100 cm3 of water, dried over sodium sulfate, filtered and concentrated under reduced pressure (1 kPa) at a temperature in the region of 50° C. The residue is purified by chromatography at atmospheric pressure on a column of silica gel (particle size 20-45μ; diameter 7 cm; mass 600 g), elution being carried out with ethyl acetate. Fractions 3 to 11 are combined and then concentrated under the above conditions. 18.4 g of methyl (3R,4R)-1-[3-(2,3,5-trifluorophenyl)prop-2-ynyl]-4-[3-oxo-3-(6-methoxyquinolin-4-yl)propyl]piperidine-3-carboxylate are obtained.

Provenance & Evidence