반응 #215038

반응 방정식

hydrochloric acid

ethyl 2-(2,2-dichlorovinyl)-3,3-dimethyl-1-ethoxycarbonylcyclopropanecarboxylate

potassium hydroxide

ethanol

→

2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane carboxylic acid

용매

water

반응 조건

후처리

1. 1
   온도is refluxed for 2 hours
2. 2
   기타The white oily precipitate which is formed
3. 3
   기타is collected by extraction with carbon tetrachloride
4. 4
   건조the extracts dried with anhydrous sodium sulphate
5. 5
   기타the solvent evaporated under reduced pressure
6. 6
   온도The residual oil is heated under nitrogen to about 150°-160° C. for about 1.5 hours
7. 7
   온도cooled
8. 8
   기타to form a crystalline mass
9. 9
   기타Recrystallisation from n-hexane

실험 절차

The mixture of ethyl 2-(2,2-dichlorovinyl)-3,3-dimethyl-1-ethoxycarbonylcyclopropanecarboxylate (1.5 g.) potassium hydroxide (2.0 g.) and ethanol (150 ml.) is refluxed for 2 hours, after which it is poured into water (500 ml.) and carefully acidified with concentrated hydrochloric acid. The white oily precipitate which is formed is collected by extraction with carbon tetrachloride, the extracts dried with anhydrous sodium sulphate, and the solvent evaporated under reduced pressure. The residual oil is heated under nitrogen to about 150°-160° C. for about 1.5 hours, and then cooled to form a crystalline mass. Recrystallisation from n-hexane yielded 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane carboxylic acid, m.p. 87°-90° C., believed to be principally the trans-isomer.

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