Pyridine → [5-(1-Methyl-cyclopropyl)-2-(6-methyl-pyridin-3-yl)-2H-pyrazol-3-yl]-carbamic acid 2,2,2-trichloro-ethyl ester

Participants

Reaction Conditions

Reaction Steps

Add a solution of 2,2,2-trichloroethylchloroformate (1.80 g, 8.5 mmol) in THF (10 mL) dropwise to an ice-salt cooled solution of 5-(1-trifluoromethyl-cyclopropyl)-2-p-tolyl-2H-pyrazol-3-ylamine (2.29 g, 8.1 mmol) and pyridine (0.9 mL, 11 mmol) in THF (30 mL) at −15° C. Stir at −15° C. for 0.5 hours and then 22° C. for 1 hour, then distribute the reaction mixture between dichloromethane (50 mL) and a saturated aq. sodium bicarbonate solution (50 mL). Isolate the aqueous phase and extract twice with dichloromethane (25 mL each). Dry the combined organic phases over sodium sulfate and concentrate. Subject residue to silica gel chromatography eluting with hexanes and ethyl acetate to give a white solid (2.46 g, 66% yield). MS(ES+): m/z=457.2 [M+H].

Provenance & Evidence