Malic Acid → Dihexyl 2-hydroxybutanedioate

HRID 840959Notes

Reaction equation

HRID 840959 reaction equation
[C:1]1([CH3:11])[CH:6]=[CH:5][C:4](S(O)(=O)=O)=[CH:3]C=1.[C:12]([OH:20])(=[O:19])[CH:13]([CH2:15][C:16]([OH:18])=[O:17])[OH:14].[CH2:21](O)[CH2:22][CH2:23][CH2:24][CH2:25][CH3:26]>O1CCOCC1>[CH2:21]([O:19][C:12](=[O:20])[CH:13]([CH2:15][C:16]([O:18][CH2:3][CH2:4][CH2:5][CH2:6][CH2:1][CH3:11])=[O:17])[OH:14])[CH2:22][CH2:23][CH2:24][CH2:25][CH3:26]

Participants

5

Reactant 3

HCID 525Malic AcidHCID 6101p-Toluenesulfonic acid2×HCID 81031-Hexanol

Product 1

HCID 177752Dihexyl 2-hydroxybutanedioate

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent2×

Conditions

Temperature
110 °C

Procedure

Dihexyl-DL-malate was prepared using a procedure similar to that in Example 4 with p-toluenesulfonic acid as the catalyst. Unlike Examples 3-7, the reaction was not performed in neat alcohol. In this case, 1,4-dioxane was added to dissolve the starting acid. To the reaction flask, DL-malic acid (80.91 g), hexyl alcohol (307 mL), 1,4-dioxane (200 mL) and p-toluenesulfonic acid (12.3 g) were added. The mixture was placed under nitrogen and heated to reflux. At 103° C., one phase started to collect in the Dean-Stark trap. The reaction temperature was increased to 110° C. and after 2 hr 40 min very little liquid had collected in the trap. The reaction temperature was increased to 115° C. and held until no more liquid collected in the trap. The product was neutralized with saturated sodium bicarbonate, diluted with diethyl ether, washed three times with saturated sodium bicarbonate, once with water and dried over magnesium sulfate. The diethyl ether was removed via rotary evaporation. Dihexyl-DL-malate was obtained as a low viscosity, clear, colorless liquid with a slight pleasant odor (127.7 g, 70% yield) after removing residual hexyl alcohol via vacuum distillation.

Workup

  1. customDihexyl-DL-malate was prepared
  2. dissolutionto dissolve the starting acid
  3. temperatureheated to reflux
  4. customAt 103° C.
  5. customto collect in the Dean-Stark trap
  6. customhad collected in the trap
  7. temperatureThe reaction temperature was increased to 115° C.
  8. customcollected in the trap
  9. additiondiluted with diethyl ether
  10. washwashed three times with saturated sodium bicarbonate
  11. dry with materialonce with water and dried over magnesium sulfate
  12. customThe diethyl ether was removed via rotary evaporation

Sources & evidence

ORD record
ord-706519f890b04bde84f6f2909b9130d7
Source dataset
uspto-grants-2002_04
Patent number
US06369146B1

Reaction notes

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