Hydrogen Bromide → 3-Bromo-5-(trifluoromethyl)pyridine

Participants

Reaction Conditions

Reaction Steps

A solution of sodium nitrite (402 mg, 5.83 mmol) in water (6.8 mL) was added slowly to a suspension of 5-(trifluoromethyl)pyridin-3-amine (947 mg, 5.55 mmol) in hydrogen bromide (48% aqueous solution, 1.57 mL) in ice-water bath. After being stirred for 10 min, the resulting orange diazo solution was directly but slowly transferred to a stirring mixture of copper(I) bromide (876 mg, 6.11 mmol) and hydrogen bromide (48% aqueous solution, 0.38 mL). The resulting brown mixture was heated at 60° C. for 1 h. After cooling to room temperature, the mixture was diluted with methylene chloride, washed with 50% NaOH (until pH=11), and water. The aqueous layer was back extracted with methylene chloride. The combined organic extracts were carefully concentrated under vacuum to provide crude product without purification.

Provenance & Evidence