Pyridine → [2-(4-Chloro-phenyl)-2,4,5,6-tetrahydro-cyclopentapyrazol-3-yl]-cyclohexyl-acetic acid pentafluorophenyl ester

Participants

Reaction Steps

To a solution of [2-(4-chloro-phenyl)-2,4,5,6-tetrahydro-cyclopentapyrazol-3-yl]-cyclohexyl-acetic acid (300 mg, 836 umol) in DMF (3 ml) was added pyridine (70 ul, 920 umol) and pentafluorophenyl trifluoroacetate (290 ul, 1.7 mmol) at ambient temperature under an argon atmosphere. The reaction mixture was stirred at ambient temperature for 12 h, poured onto ice water/0.1 N HCl 1/1 and extracted two times with iPrOAc. The combined extracts were washed with ice water/sat. aqueous NaHCO3 solution 1/1, ice water/brine 1/1 and dried over Na2SO4. After filtration the solvent was removed under reduced pressure to give [2-(4-chloro-phenyl)-2,4,5,6-tetrahydro-cyclopentapyrazol-3-yl]-cyclohexyl-acetic acid pentafluorophenyl ester as an orange oil (762 mg; quant.) which was directly used in the next reaction step without further purification.

Provenance & Evidence