Hydrochloric Acid → Fmoc-L-aspartic acid

HRID 849441Notes

Reaction equation

HRID 849441 reaction equation
C1C(=O)N([O:8][C:9]([O:11][CH2:12][CH:13]2[C:25]3[C:20](=[CH:21][CH:22]=[CH:23][CH:24]=3)[C:19]3[C:14]2=[CH:15][CH:16]=[CH:17][CH:18]=3)=O)C(=O)C1.[NH2:26][C@H:27]([C:32]([OH:34])=[O:33])[CH2:28][C:29]([OH:31])=[O:30].C([O-])([O-])=O.[Na+].[Na+].Cl>O.O1CCOCC1>[C:9]([NH:26][C@H:27]([C:32]([OH:34])=[O:33])[CH2:28][C:29]([OH:31])=[O:30])([O:11][CH2:12][CH:13]1[C:14]2[C:19](=[CH:18][CH:17]=[CH:16][CH:15]=2)[C:20]2[C:25]1=[CH:24][CH:23]=[CH:22][CH:21]=2)=[O:8]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 5960L-Aspartic AcidHCID 10340Sodium Carbonate2×HCID 134122N-(9-Fluorenylmethoxycarbonyloxy)succinimide

Product 1

HCID 7019016Fmoc-L-aspartic acidYield 71%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

Forty-five g (0.134 M, 0.96 eq) of Fmoc-Osu was added to 20 g (0.15 M, 1 eq) of aspartic acid and 20 g of Na2CO3 dissolved in 400 mL of water and 200 mL of dioxane. The mixture was stirred for 2 hrs while the pH was maintained at about 9 by the addition of small amounts of Na2CO3. Then the cloudy white mixture was poured into 500 mL of ice water containing 40 mL of conc HCl. The white solid was extracted with 500 mL EtOAc and this was mixed with 500 mL of hexane. The mixture was chilled overnight and stirred the next day to give 38 g of Fmoc-aspartic acid as crystals (71% yield) upon filtration and air drying. 10 g (0.28 M) of this product was dissolved in 200 mL of methanol and 20 mL of conc H2SO4 was added. The solution was allowed to stand overnight. The mixture was poured into 1 L of water and filtered. The resulting white solid was dried and redissolved in EtOAc. Slow addition of hexane and chilling gave 9 g (83% yield) of product as white needles, mp 78-80°. [a]d =-13.9°.

Workup

  1. extractionThe white solid was extracted with 500 mL EtOAc
  2. additionthis was mixed with 500 mL of hexane
  3. temperatureThe mixture was chilled overnight
  4. stirringstirred the next day

Sources & evidence

ORD record
ord-f6a1b5ec6e01497988ae1d8233045995
Source dataset
uspto-grants-2000_01
Patent number
US06013462

Reaction notes

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