Sulfuric Acid → 4-(trifluoromethyl)hepta-1,6-dien-4-ol

HRID 426524Notes

Reaction equation

HRID 426524 reaction equation
[CH2:1](Br)[CH:2]=[CH2:3].[Mg].[F:6][C:7]([F:14])([F:13])[C:8]([O:10]CC)=O.S(=O)(=O)(O)O.[CH2:20]([Mg:23][Br:24])[CH:21]=[CH2:22]>O1CCCC1.CCOCC>[CH2:20]([Mg:23][Br:24])[CH:21]=[CH2:22].[OH:10][C:8]([C:7]([F:6])([F:13])[F:14])([CH2:22][CH:21]=[CH2:20])[CH2:1][CH:2]=[CH2:3]

Participants

9

Reactant 5

HCID 1118Sulfuric AcidHCID 7841Allyl bromideHCID 9794Ethyl trifluoroacetateHCID 5462224MagnesiumHCID 178455850HCID 178455850, compound

Product 2

HCID 111596554-(trifluoromethyl)hepta-1,6-dien-4-olYield 70%HCID 178455850HCID 178455850, compound

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

Allylmagnesium bromide was prepared from 140 g (1.16 mole) of allyl bromide, 35 g (1.44 mole) of magnesium and 640 ml of ether. The product was titrated and found to be 1.2 molar in allylmagnesium bromide. To a 230 ml (0.276 mole) aliquot of the reagent was added 17.4 g (0.122 mole) of ethyl trifluoroacetate in 60 ml of dry tetrahydrofuran at a drop rate of 2-3 drops/second. The reaction temperature was held near -40° during the addition. The reaction mixture was allowed to warm to room temperature and stirred overnight. It was heated at reflux for two hours, then stirred for an additional 24 hours. The reaction mixture was poured into 300 ml of ice and 20% sulfuric acid was added to bring the pH to about 1. The phases were separated and the aqueous phase extracted with 3×70 ml of ether. The combined organic phases were dried over magnesium sulfate, filtered and the solvent evaporated. The liquid product was distilled in vacuo to give 15.2 g (70%) of 4-hydroxy-4-trifluoromethyl-1,6-heptadiene, bp 54.5-58.5° C./30 torr.

Workup

  1. additionThe reaction temperature was held near -40° during the addition
  2. temperatureIt was heated
  3. temperatureat reflux for two hours
  4. stirringstirred for an additional 24 hours
  5. additionwas added
  6. customThe phases were separated
  7. extractionthe aqueous phase extracted with 3×70 ml of ether
  8. dry with materialThe combined organic phases were dried over magnesium sulfate
  9. filtrationfiltered
  10. customthe solvent evaporated
  11. distillationThe liquid product was distilled in vacuo

Sources & evidence

ORD record
ord-5aa3b6e8654b4a87b2174384f683ce43
Source dataset
uspto-grants-1979_10
Patent number
US04169944

Reaction notes

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