Benzyl Alcohol → L-Glutamic acid, 5-(phenylmethyl) ester

HRID 1248640Notes

Reaction equation

HRID 1248640 reaction equation
[NH2:1][C@H:2]([C:8]([OH:10])=[O:9])[CH2:3][CH2:4][C:5]([OH:7])=[O:6].S(=O)(=O)(O)O.[CH2:16](O)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>>[CH:20]1[CH:21]=[CH:22][C:17]([CH2:16][O:6][C:5]([CH2:4][CH2:3][C@H:2]([NH2:1])[C:8]([OH:10])=[O:9])=[O:7])=[CH:18][CH:19]=1

Participants

4

Reactant 3

HCID 244Benzyl AlcoholHCID 1118Sulfuric AcidHCID 33032L-Glutamic Acid

Product 1

HCID 122337L-Glutamic acid, 5-(phenylmethyl) esterYield 45.7%

Conditions

Temperature
70 °C

Procedure

1416 grams (g) of L-glutamic acid, 1560 g of 60% sulfuric acid and 1152 g of benzyl alcohol were placed in a 12 liter round bottom flask equipped with a distillation head. The mixture was heated to 70° C. and stirred for 45 minutes. Upon cooling, the resulting solution was stirred and was subjected to a reduced pressure. When the vacuum had stabilized at about 100 millimeters (mm) the reaction temperature was again raised to 70° C. and water was distilled off for about 4.5 hours. Upon standing overnight, the reaction mixture became viscous and was slowly added to a stirred mixture of 1613 g of sodium bicarbonate, 1.2 kilograms (kg) of ice and 12 liters of water. A precipitate formed which was collected by filtration and then washed with about 8 liters of carbon dioxide-free water and 8 liters of acetone and subsequently air-dried. The precipitate was triturated with 2 liters of ether and dried, yielding 1044 g of the desired γ-benzyl L-glutamate, melting point (m.p.) 156°-157° C. Thin layer chromatography detected the presence of unreacted glutamic acid in the crude product. The crude product was recrystallized from 12.5 liters of hot water and filtered through a plug of glass wool suspended in the neck of a heated glass funnel. After cooling, and overnight refrigeration, the recrystallized product was collected, and washed with 2 liters of cold water, then 2 liters of THF. The product was air dried overnight and then dried in vacuo at room temperature for three hours. 693 g of γ-benzyl L-glutamate was recovered as white, shiny plates, m.p. 156.5°-157° C.

Workup

  1. customequipped with a distillation head
  2. temperatureUpon cooling
  3. stirringthe resulting solution was stirred
  4. temperaturewas again raised to 70° C.
  5. distillationwater was distilled off for about 4.5 hours
  6. waitUpon standing overnight
  7. additionwas slowly added to a stirred mixture of 1613 g of sodium bicarbonate, 1.2 kilograms (kg) of ice and 12 liters of water
  8. customA precipitate formed which
  9. filtrationwas collected by filtration
  10. washwashed with about 8 liters of carbon dioxide-free water and 8 liters of acetone
  11. customsubsequently air-dried
  12. customThe precipitate was triturated with 2 liters of ether
  13. customdried

Sources & evidence

ORD record
ord-1f27533623de448587c8781c8bd5da41
Source dataset
uspto-grants-1985_06
Patent number
US04525495

Reaction notes

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