Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → {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 colourless solution of Intermediate 39b (120 mg, 0.224 mmol) and pyridinium p-toluenesulfonate (169 mg, 0.673 mmol) in MeOH (5 mL) was stirred at 40° C. for 90 min. The solution was concentrated in vacuo, suspended in water (3 mL) and sat. aq. NaHCO3 solution (3 mL), then extracted with DCM (2×5 mL). The combined organics were passed through a hydrophobic frit, concentrated in vacuo and azeotroped with toluene (2×5 mL) to leave the title compound as a white solid (100 mg, 99%). LCMS (Method 3): Rt 4.01 min, m/z 450, 452 [MH+].

Provenance & Evidence