Formic Acid → 4-(1H-Pyrazol-1-yl)benzaldehyde

Participants

Reaction Steps

To a solution of 4-pyrazol-1-yl-benzonitrile (1.6 g, 9.47 mmol), prepared in Step A of Preparation 42, in 75% aqueous formic acid (36 mL) was added Raney nickel alloy (1.6 g). The reaction was heated at reflux for 1.25 h and was cooled to room temperature. The solids were removed by filtration through Celite with the aid of hot EtOH. The solution was diluted with water and CHCl3. The aqueous layer was washed with CHCl3 (3×). To the organic solution was carefully added aqueous NaHCO3 until a pH of about 8 was achieved. The organic layer was dried (MgSO4), filtered, and concentrated. Purification by medium pressure chromatography (2:1 hexanes:EtOAc) provided the title compound (1.44 g) as a white solid. 1H NMR (400 MHz, CDCl3) δ 9.99 (s, 1H), 8.01 (d, 1H), 7.96 (d, 2H), 7.87 (d, 2H), 7.76 (d, 1H), 6.51 (m, 1H); MS 173 (M+1).

Provenance & Evidence