反应详情

A mixture of ethyl 2-(2,2-dichlorovinyl)-3,3-dimethyl-1-ethoxycarbonylcyclopropane carboxylate (5.0 g.), sodium chloride (0.95 g.), and `wet` dimethylsulphoxide (6.0 ml.) was heated at a temperature of 175° to 180° C. under a nitrogen atmosphere for a period of 6 hours, after which it was cooled to the ambient temperature poured into water and extracted with petroleum ether (boiling range 60° to 80° C.). The extracts were dried over anhydrous magnesium sulphate and concentrated by evaporation of the solvent to yield a residue comprising about 60% of the cis-isomer and 40% of the trans-isomer of ethyl 2-(2,2-dichlorovinyl)-3,3-dimethylcyclopropane carboxylate in about 80% yield, identification of which was confirmed by comparison with authentic samples using infra-red spectroscopy and gas-liquid chromatography.

1. extractionextracted with petroleum ether (boiling range 60° to 80° C.)
2. dry with materialThe extracts were dried over anhydrous magnesium sulphate
3. concentrationconcentrated by evaporation of the solvent