Hexane → 2-Methyl-4-methylenepentanedioic acid

HRID 614673Notes

Reaction equation

HRID 614673 reaction equation
P(Cl)(Cl)Cl.C(NCCC)CC.CCCCCC.[CH2:18]=[C:19]([CH2:31][CH:32]([C:34]([O:36]C)=[O:35])[CH3:33])[C:20]([O:22]CC(CC)CCCC)=[O:21]>O>[CH2:33]=[C:32]([CH2:31][CH:19]([CH3:18])[C:20]([OH:22])=[O:21])[C:34]([OH:36])=[O:35]

Participants

6

Reactant 4

HCID 8058HexaneHCID 8902DipropylamineHCID 24387Phosphorus trichlorideHCID 53650234HCID 53650234, compound2×

Product 1

HCID 197840522-Methyl-4-methylenepentanedioic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Phosphorus trichloride (6.85 g.) is added dropwise and continuously to a stirred solution containing 30.4 g. of di-n-propylamine dissolved in 100 ml. of hexane at 10° C. After complete addition, the reaction mixture is allowed to stir 1 hour at room temperature. Sufficient water (75 ml.) is then added to dissolve the amine salt formed, and the organic layer is separated. The organic layer is washed once with 75 ml. of water. Methyl methacrylate (1000 g.) and 2 g. of the methyl ether of hydroquinone are added to the organic layer and heated to 65° C. To this stirred solution, 276 g. of 2-ethylhexyl acrylate is added dropwise over 8 to 10 hours. After a total of 24 hours at 65° C., the hexane and unconverted esters are removed via distillation. The residue is distilled to give 200 g. of 2-ethylhexyl 2-methylene-4-carbomethoxypentanoate, b.p. 120°-125° C./0.1 mm, nD25 = 1.4452-1.4463 and 164 g. of di-2-ethylhexyl glutarate, b.p. 150°-155° C./0.1 mm, nD25 = 1.4513. The 2-ethylhexyl 2-methylene-4-carbomethoxypentanoate is saponified to give 2-methylene-4-methylglutaric acid having a melting point of 106° to 108° C. and an acid number of 727. This product is further identified by elemental analysis and nmr spectroscopy.

Workup

  1. additioncontaining 30.4 g
  2. customat 10° C
  3. additionAfter complete addition
  4. customformed
  5. customthe organic layer is separated
  6. washThe organic layer is washed once with 75 ml
  7. additionof the methyl ether of hydroquinone are added to the organic layer
  8. temperatureheated to 65° C
  9. additionof 2-ethylhexyl acrylate is added dropwise over 8 to 10 hours
  10. customAfter a total of 24 hours at 65° C., the hexane and unconverted esters are removed via distillation
  11. distillationThe residue is distilled
  12. customto give 200 g

Sources & evidence

ORD record
ord-0adda0d25a4c417c9c3fc06fff6e74db
Source dataset
uspto-grants-1979_03
Patent number
US04145559

Reaction notes

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