Hydrogen Bromide → HCID 9891091, compound

Participants

Reaction Steps

To a solution of 1-(3-amino-4-methoxyphenyl)-5-[4-(methylsulfonyl)phenyl]-3-(trifluoromethyl)pyrazole hydrochloride (0.80 g) in ca. 24% hydrobromic acid (16 ml) was added a solution of sodium nitrite (0.14 g) in water (1 ml) while the internal temperature of the reaction mixture was maintained below 0° C. The above mixture was added to an ice-cooled solution of copper(I) bromide (0.30 g) in ca. 24% hydrobromic acid (8 ml) and the mixture was stirred at ambient temperature for 1.5 hours. The reaction mixture was extracted with ethyl acetate and the organic layer was washed with brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (elution with chloroform) to give the product, which was recrystallized from diisopropyl ether (3 ml)-ethyl acetate (3 ml) to give 1-(3-bromo-4-methoxyphenyl)-5-[4-(methylsulfonyl)phenyl]-3-(trifluoromethyl)-pyrazole (0.39 g).

Provenance & Evidence