2-Bromoisovaleric acid → 2-[(2,3-Dichloro-4-methoxyphenyl)sulfanyl]-3-methylbutanoic acid

Participants

Reaction Steps

To 3.13 g of 99% sodium hydride under nitrogen at room temperature is added a solution of 12.26 g of 2,3-dichloro-4-methoxythiophenol in 100 ml of sieve-dried dimethylformamide over 2 minutes. The reaction is stirred for 12 minutes. A solution of 9.56 g of α-bromoisovaleric acid in 85 ml of dimethylformamide is added over 4 minutes. The reaction is stirred at room temperature for 3 hours, cooled in ice, diluted with 500 ml of water and filtered. The solution is cooled and acidified with 3 N hydrochloric acid to give the product. The precipitate is filtered, washed with a small amount of water, dried and recrystallized from acetone-pentane to give 13.14 g of α-(2,3-dichloro-4-methoxyphenylthio)isovaleric acid as a white crystalline powder mp 176.5°-178.5°.

Provenance & Evidence