Sodium Hydroxide → {5-tert-Butyl-2-[3-(2-hydroxy-ethoxy)-phenyl]-2H-pyrazol-3-yl}-carbamic acid 2,2,2-trichloro-ethyl ester

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Reaction Steps

A solution of Intermediate 186a (1.0 g, 3.63 mmol) in EtOAc (20 mL) was treated with aqueous NaOH (1M, 6.53 mmol), followed by 2,2,2-trichloroethyl chloroformate (0.529 mL, 3.85 mmol) and the reaction mixture was stirred at RT for 1 h. The mixture was partitioned between EtOAc (20 mL) and water (20 mL). The layers were separated and the aqueous layer was extracted with a further 20 mL EtOAc. The combined organic layers were dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by FCC, using 0-40% EtOAc in DCM. The combined fractions were evaporated under reduced pressure and the product was triturated with DCM. The solid was filtered and washed with Diethyl ether to afford the title compound as a white solid (0.930 g, 58%). LCMS (Method 3): Rt 4.01 min, m/z 450 [M].

Provenance & Evidence