Hydrochloric Acid → 5-tert-Butyl-2-[3-(4,4-difluoro-piperidin-1-ylmethyl)-phenyl]-2H-pyrazol-3-ylamine

Participants

Reaction Steps

A mixture of Intermediate 12b (1.30 g, 2.94 mmol), pivaloyl acetonitrile (0.37 g, 2.94 mmol), and concentrated HCl (1.5 mL) in ethanol (10 mL) was heated under reflux for 3 h. The cooled mixture was taken to ca. pH 7 with aqueous saturated NaHCO3, and the mixture partitioned between water (15 mL) and EtOAc (3×15 mL). The combined organic extracts were washed with brine (20 mL) and dried (Na2SO4). The solvent was evaporated, and the residue purified by FCC, eluting with 0-100% EtOAc in pentane, to give the title compound as a pale yellow solid (450 mg, 43%). LCMS (Method 1): Rt 1.93 min, m/z 349 [MH+].

Provenance & Evidence