Hydrochloric Acid → Permethric acid

HRID 127856

Reaction equation

HRID 127856 reaction equation
[Cl:1][C:2]([Cl:19])=[CH:3][CH:4]1[C:6]([CH3:8])([CH3:7])[C:5]1(C(OCC)=O)[C:9]([O:11]CC)=[O:10].[OH-].[K+].C(O)C.Cl>O>[CH3:7][C:6]1([CH3:8])[CH:4]([CH:3]=[C:2]([Cl:19])[Cl:1])[CH:5]1[C:9]([OH:11])=[O:10]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 702EthanolHCID 14797Potassium HydroxideHCID 14914133Ethyl 2-(2,2-dichlorovinyl)-3,3-dimethyl-1-ethoxycarbonylcyclopropanecarboxylate

Product 1

HCID 91658Permethric acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

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.

Workup

  1. temperatureis refluxed for 2 hours
  2. customThe white oily precipitate which is formed
  3. customis collected by extraction with carbon tetrachloride
  4. dry with materialthe extracts dried with anhydrous sodium sulphate
  5. customthe solvent evaporated under reduced pressure
  6. temperatureThe residual oil is heated under nitrogen to about 150°-160° C. for about 1.5 hours
  7. temperaturecooled
  8. customto form a crystalline mass
  9. customRecrystallisation from n-hexane

Sources & evidence

ORD record
ord-a4acd62499ac4d6cb313d58794d52ef5
Source dataset
uspto-grants-1981_03
Patent number
US04257975

Linked notes

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