Trifluoroacetic acid → HCID 22718086, compound

Participants

Reaction Steps

A solution of 2-[5-[4-(4-fluorophenoxy)phenyl]-pyrazol-1-yl]ethanol (118 mg, 0.40 mmol) in 1 mL of toluene was treated with solid sodium cyanate (2 eq.; 53 mg, 0.82 mmol) added in one portion. The resulting mixture was cooled in an ice-water bath and neat trifluoroacetic acid (60 μL, 89 mg, 0.78 mmol) was added dropwise via syringe. The reaction was stirred at room temperature. After 2 hours, the reaction had completely solidified and an additional 1 mL of toluene was added. After stirring overnight, the reaction was recooled to 0° C. and diluted with 3 mL of a saturated aqueous NaHCO3 solution. The aqueous layer was separated and extracted with EtOAc (3×5 mL). The organic layers were combined, washed with brine, dried (Na2SO4), filtered and concentrated. Column chromatography (13 cm of flash silica in a 2 cm diameter column eluted with 600 mL of 3:2 CH2Cl2/EtOAc) afforded 21 mg (15%) of the carbamate as a solid, mp 120-125° C. 1H NMR (CDCl3): δ7.57 (d, 1H, J=2 Hz), 7.35 (d, 2H, J=9 Hz), 7.10-7.05 (m, 4H), 7.02 (d, 2H, J=9 Hz), 6.26 (d, 1H, J=2 Hz), 4.60 (br s, 2H), 4.43 (t, 2H), 4.35 (t, 2H).

Provenance & Evidence