Potassium Hydroxide → Permethric acid

Participants

Reaction Steps

24.7 g. of 2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropane-1-carboxylic acid ethyl ester (purity: 96%, cis)trans ratio: 40:60), 6.7 g. of a 30% aqueous potassium hydroxide solution and 0.05 g. of polyoxyethylenesorbitane monooleate are stirred at 70° C. for 60 minutes. Stirring is continued with a further 6-g. portion of the potassium hydroxide solution for 60 minutes and with an additional 6-g. portion for 120 minutes. The solution is diluted with 100 ml. of water and 40 ml. fraction is distilled off to remove volatile, non-hydrolyzed substances. To the residual aqueous solution 80 cm3 of hexane is added followed by the addition of 12 g. of a 36% aqueous hydrochloric acid solution at 60° C. with stirring. The reaction mixture is then further manufactured as described in Example 1. 19.8 g. (95%) of 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane-1-carboxylic acid are obtained. Cis/trans ratio: 40:60.

Provenance & Evidence