Water → 5-(Bromomethyl)thiophene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

In 840 ml of carbon tetrachloride were suspended 100 g of 5-methyl-2-thiophenecarboxylic acid, 125.2 g of N-bromosuccinimide and 7 g of benzoyl peroxide. The suspension was heated to 90° C. with vigorous agitation. After the reaction started, the reaction temperature was raised to 100° C. and agitation was continued for 2 hours at the same temperature. The reaction mixture was cooled to 0° C., and 500 ml of n-hexane was added thereto. Precipitated crystals were collected by filtration and washed with 100 ml of n-hexane. The obtained crude crystals were suspended in 2 of water and the suspension was stirred at room temperature for 10 minutes. The suspended crystals were collected again by filtration and washed with 200 ml of water. The obtained crystals were recrystallized from ethanol-water to give 84 g of the desired 5-bromomethyl-2-thiophenecarboxylic acid as colorless crystals.

Provenance & Evidence