Nitric Acid → Methyl 4-bromo-5-nitrothiophene-2-carboxylate

Participants

Reaction Steps

The nitrating mixture (HNO3 d=1.42, 2 mL; concentrated H2SO4, 6 mL) was slowly added with stirring, at −5 to −10° C., to 4-Bromothiophene-2-carboxylic acid methyl ester (3 g, 13.57 mmol) dissolved in concentrated H2SO4 (10 mL). After being kept at −5 to −10° C. for 30 min. the mixture was poured over crushed ice. The solid precipitate was separated by filtration and washed with water and dried over P2O5 to give 3.7 g of 4-bromo-5-nitrothiophene-2-carboxylic acid methyl ester as a tan solid, which was used in the next step without further purification.

Provenance & Evidence