Carbon tetrabromide → 1-benzyl-4-(bromomethyl)-3-nitro-1H-pyrazole

Participants

Reaction Steps

Carbon tetrabromide (3.67 g, 11.1 mmol) and triphenylphosphine (2.43 mL, 11.1 mmol) were added to a solution of C3 (1.29 g, 5.53 mmol) in dichloromethane (150 mL), and the reaction was allowed to stir at RT for 18 hours. After being washed with water, the reaction mixture was dried over magnesium sulfate, filtered, and concentrated under reduced pressure. Silica gel chromatography (Gradient: 0% to 100% EtOAc in heptane) afforded C4 as a solid. Yield: 951 mg, 3.21 mmol, 58%. LCMS m/z 297.9 (M+1). 1H NMR (400 MHz, CDCl3) δ 4.60 (d, J=0.6 Hz, 2H), 5.32 (s, 2H), 7.28-7.32 (m, 2H), 7.36-7.41 (m, 3H), 7.52 (br s, 1H).

Provenance & Evidence