Glycine → (S)-2-Cyclopentyloxycarbonylamino-3,3-dimethyl-butyric acid

HRID 387199

Reaktionsgleichung

Reaktionsgleichung von HRID 387199
[C:1](NCC(O)=O)([CH3:4])([CH3:3])[CH3:2].[C:10](=[O:25])(ON1C(=O)CCC1=O)[O:11][CH:12]1[CH2:16][CH2:15][CH2:14][CH2:13]1.[NH2:26][CH2:27][C:28]([OH:30])=[O:29]>C(=O)(O)[O-].[Na+].CC(C)=O>[CH:12]1([O:11][C:10]([NH:26][C@@H:27]([C:1]([CH3:4])([CH3:3])[CH3:2])[C:28]([OH:30])=[O:29])=[O:25])[CH2:13][CH2:14][CH2:15][CH2:16]1

Komponenten

6

Edukt 3

HCID 750GlycineHCID 414246N-tert-ButylglycineHCID 15927743N-(Cyclopentyloxycarbonyloxy)succinimide

Produkt 1

HCID 23595129(S)-2-Cyclopentyloxycarbonylamino-3,3-dimethyl-butyric acid

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 180AcetoneLösungsmittelHCID 516892Sodium BicarbonateLösungsmittel

Versuchsvorschrift

In a 5 L RB flask dissolved t-butyl glycine (74 g, 0.56 mol, 1.02 eq.) in saturated sodium bicarbonate (11 vol). Cyclopentyl 2,5-dioxopyrrolidin-1-yl carbonate (126 g, 0.55 mol, 1 eq.) was dissolved in acetone (5.5 vol) and the solution slowly added via addition funnel at room temperature to the solution of the glycine. The reaction mixture was stirred at room temperature until complete (approximately 4 hours). The acetone was removed under reduced pressure and the remaining aqueous solution was extracted with 30% ethyl acetate in hexanes (thrice, 5.5 vol each). The organic layers were discarded. The pH of the aqueous layer was adjusted to 2 with 2 N HCl and then extracted with ethyl acetate (thrice, 5.5 vol). The combined organic layers were dried (Na2SO4), filtered, and the solvent removed under reduced pressure to provide a clear oil the slowly crystallized. The crude product was crystallized from hexanes/ethyl acetate to provide (S)-2-(cyclopentyloxycarbonylamino)-3,3-dimethylbutanoic acid as a white solid (82 g). The mother liquid was stripped and a second crop of crystals obtained (combined yield 105.54 g).

Aufarbeitung

  1. customThe acetone was removed under reduced pressure
  2. extractionthe remaining aqueous solution was extracted with 30% ethyl acetate in hexanes (thrice, 5.5 vol each)
  3. extractionextracted with ethyl acetate (thrice, 5.5 vol)
  4. dry with materialThe combined organic layers were dried (Na2SO4)
  5. filtrationfiltered
  6. customthe solvent removed under reduced pressure
  7. customto provide a clear oil the
  8. customslowly crystallized
  9. customThe crude product was crystallized from hexanes/ethyl acetate

Quellen und Nachweise

ORD-Eintrag
ord-30b7d5edbbf64fa2bbc073d4973d7d15
Quelldatensatz
uspto-grants-2013_02
Patentnummer
US08372873B2

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