Isoamyl Nitrite → Ethyl 5-bromo-1-phenyl-1H-pyrazole-4-carboxylate

Participants

Reaction Steps

To a solution of 20.0 g of 5-amino-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester and 10 ml of bromine in 200 ml of chloroform was added 15.8 g of isoamyl nitrite dropwise. The reaction mixture was allowed to stir at room temperature for about 24 hours and the volatiles were removed under reduced pressure. The residue was recrystallized from ethanol/water to provide 10.0 g of 5-bromo-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester. Yield 38%. mp=86°-89° C.

Provenance & Evidence