tert-Butyl piperazine-1-carboxylate → 5-[3-(4-BOC-piperazin-1-yl)-pyridin-5-yl]-1-(2,4-difluoro-phenyl)-3-pentafluoroethyl-4,5-dihydro-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

5-(3-Bromo-pyridin-5-yl)-1-(2,4-difluoro-phenyl)-3-pentafluoroethyl-4,5-dihydro-1H-pyrazole (340.0 mg, 0.75 mmol) prepared in Step 4 of Preparation 10, 1-BOC-piperazine (208.0 mg, 1.12 mmol), Pd2(dba)3 (34.1 mg, cat.), BINAP (46.4 mg, cat.) and sodium t-butoxide (128.9 mg, 1.34 mmol) were added to toluene (10.0 mL). The reaction mixture was stirred at 100° C. for 12 hours and then filtered through celite pad. A saturated solution of ammonium chloride was added to the filtrate, which was then extracted with ethyl acetate three times. The combined extract was washed with brine, dried on anhydrous magnesium sulfate, and then concentrated under reduced pressure to give a yellow liquid residue. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/3) to give 220.0 mg of the titled compound as a yellow liquid.

Provenance & Evidence