Benzoyl Peroxide → tert-butyl 4-(bromomethyl)-1H-pyrazole-1-carboxylate

Participants

Reaction Steps

To a solution of 4-methylpyrazole-1-carboxylic acid tert-butyl ester (1.0 g, 5.5 mmol) in carbon tetrachloride (20 mL) was added N-bromosuccinimide (1.0 g, 5.6 mmol) and benzoyl peroxide (50 mg), and the reaction mixture was heated at reflux for 16 h. The reaction mixture was cooled to room temperature, filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:4 EtOAc/hexanes) provided 4-bromomethylpyrazole-1-carboxylic acid tert-butyl ester as a light yellow oil (0.42 g, 30%): 1NMR (300 MHz, CDCl3) δ 8.10 (s, 1H), 7.74 (s, 1H), 4.39 (s, 2H), 1.65 (s, 9H).

Provenance & Evidence