反应详情

30.8 g (0.085 mol) of 2,2-dimethyl-3-(2-chloro-2-(4-trifluoromethoxy-phenyl)-vinyl)-cyclopropanecarboxylic acid ethyl ester were dissolved in 100 ml of ethanol, a solution of 4 g (0.1 mol) of sodium hydroxide in 100 ml of water was then added and the mixture was heated to the reflux temperature for 4 hours, while stirring. The ethanol was then distilled off under a waterpump vacuum, the residue was taken up in 300 ml of warm water and the mixture was extracted once with 300 ml of methylene chloride. The aqueous phase was separated off, acidified with concentrated hydrochloric acid and then extracted with 2 times 300 ml of methylene chloride. The organic phase was then separated off and dried over magnesium sulphate and the solvent was distilled off under a waterpump vaccum. Last residues of solvent were removed by brief incipient distillation under 2 mm Hg at a bath temperature of 60° C. 19.4 g (68.3% of theory) of 2,2-dimethyl-3-(2-chloro-2-(4-trifluoromethoxy-phenyl)-vinyl)-cyclopropanecarboxylic acid (cis and trans, E and Z isomer mixture) were then obtained as a very viscous yellow oil. The structure was confirmed by the 1H-NMR spectrum.

1. temperaturethe mixture was heated to the reflux temperature for 4 hours
2. distillationThe ethanol was then distilled off under a waterpump vacuum
3. extractionthe mixture was extracted once with 300 ml of methylene chloride
4. customThe aqueous phase was separated off
5. extractionextracted with 2 times 300 ml of methylene chloride
6. customThe organic phase was then separated off
7. dry with materialdried over magnesium sulphate
8. distillationthe solvent was distilled off under a waterpump vaccum
9. customLast residues of solvent were removed by brief incipient distillation under 2 mm Hg at a bath temperature of 60° C