Sodium Bicarbonate → 4-(5-Amino-3-tert-butyl-pyrazol-1-yl)phenol

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Reaction Steps

Intermediate 13a (10.0 g, 40.8 mmol) was dissolved in DCM (80.0 mL), and aluminium trichloride (28.0 g, 204.0 mmol) was added portionwise. The reaction was heated to reflux for 4 h. Additional aluminium trichloride (28.0 g, 204.0 mmol) was added portionwise, and the reaction heated at reflux overnight. After cooling, the mixture was carefully added portionwise to saturated aqueous NaHCO3 (300 mL). The mixture was extracted with ethyl acetate (300 mL) and separated. The aqueous layer was filtered under vacuo and acidified with 1N HCl until pH=7. This aqueous layer was then re-extracted into ethyl acetate, and the organic extracts were dried (MgSO4) and evaporated in vacuo. Purification by FCC, using 0-40% EtOAc in DCM, gave the title compound (5.0 g, 21.6 mmol, 53%). LCMS (method 1): Rt 2.77 min, m/z 232/233 [MH+].

Provenance & Evidence