Sodium Hydroxide → (5-(Cyano-dimethyl-methyl)-2-{3-[2-(tetrahydro-pyran-2-yloxy)-ethoxy]-phenyl}-2H-pyrazol-3-yl)-carbamic acid 2,2,2-trichloro-ethyl ester

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Reaction Steps

Intermediate 20c (317 mg, 0.86 mmol) was dissolved in EtOAc (2.5 mL) and 1M NaOH solution (1.4 mL, 2.14 mmol) and cooled in an ice bath. While stirring, 2,2,2-trichloroethyl chloroformate (227 mg, μL, 1.07 mmol) was then added dropwise, and the ice bath removed. After 30 min, a further 0.65 eq. of 2,2,2-trichloroethyl chloroformate was added, and the reaction continued. After 30 min, a further 0.65 eq. of 2,2,2-trichloroethyl chloroformate was added, and the reaction continued overnight. The reaction was then partitioned between H2O and EtOAc, the organic layer was separated, and the aqueous layer extracted again with EtOAc. The combined organics were dried over MgSO4, concentrated in vacuo and subjected to FCC, eluting with 5-30% EtOAc in cyclohexane, to afford the title compound as a light yellow oil (375 mg, 80%). LCMS (Method 3): Rt 4.41 min, m/z 567, 569 [M+Na].

Provenance & Evidence