Potassium Hydroxide → 3-Methyl-4-phenylbut-3-enoic acid

HRID 1395606Notes

Reaction equation

HRID 1395606 reaction equation
P(Cl)(Cl)(Cl)=O.[CH3:6][C:7](=[CH:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[CH2:8][C:9]([O:11]CC)=[O:10].CC(CC1C=CC=CC=1)=CC(OCC)=O.[OH-].[K+]>O.CO.N1C=CC=CC=1>[CH3:6][C:7](=[CH:14][C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1)[CH2:8][C:9]([OH:11])=[O:10]

Participants

7

Reactant 4

HCID 14797Potassium HydroxideHCID 24813Phosphorus oxychlorideHCID 293435Ethyl 3-methyl-4-phenyl-3-butenoateHCID 293436Ethyl 3-methyl-4-phenylbut-2-enoate

Product 1

HCID 2934493-Methyl-4-phenylbut-3-enoic acid

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 22242641Methanol--water (1/1)Solvent

Procedure

To mixture of the above hydroxy-ester (3.06 g, 13.76 mmole) and pyridine (10 ml), cooled to 0°, is slowly added phosphorus oxychloride (3.59 g, 23.39 mmole). The reaction mixture is stirred for about 2 hrs and then heated to 100° for 1.5 hours. The reaction is worked up by pouring into ice and extracting with water-hexane. The aqueous layer is back-extracted with hexane. The organic phases are combined, washed with 2 N hydrochloric acid, water and brine, dried over sodium sulfate and rotoevaporated to yield a mixture of esters--ethyl 3-methyl-4-phenyl-3-butenoate and ethyl 3-methyl-4-phenyl-2-butenoate. The mixture of esters is hydrolyzed using potassium hydroxide, water/methanol at 40° for about 20 hrs to yield the acids, 3-methyl-4-phenyl-3-butenoic acid and some 3-methyl-4-phenyl-2-butenoic acid.

Workup

  1. temperaturecooled to 0°
  2. temperatureheated to 100° for 1.5 hours
  3. additionby pouring into ice
  4. extractionextracting with water-hexane
  5. extractionThe aqueous layer is back-extracted with hexane
  6. washwashed with 2 N hydrochloric acid, water and brine
  7. dry with materialdried over sodium sulfate
  8. customto yield
  9. customat 40°
  10. customfor about 20 hrs

Sources & evidence

ORD record
ord-5d91e9d3993d4a4b87029c6a815325b8
Source dataset
uspto-grants-1980_05
Patent number
US04204071

Reaction notes

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