1-(1,1-Dimethylethyl) 2-ethyl (2S)-5-oxo-1,2-pyrrolidinedicarboxylate → (S)-2-tert-Butoxycarbonylamino-5-oxo-hexanoic acid ethyl ester

HRID 1504325Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1504325
[CH3:1][CH2:2][O:3][C:4]([C@@H:6]1[CH2:10][CH2:9][C:8](=[O:11])[N:7]1[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[O:5].[CH3:19][Mg]Br>C1COCC1>[CH2:2]([O:3][C:4](=[O:5])[C@@H:6]([NH:7][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:10][CH2:9][C:8](=[O:11])[CH3:19])[CH3:1]

Komponenten

4

Edukt 2

HCID 54611861-(1,1-Dimethylethyl) 2-ethyl (2S)-5-oxo-1,2-pyrrolidinedicarboxylateHCID 178418573HCID 178418573, Verbindung

Produkt 1

HCID 58544329(S)-2-tert-Butoxycarbonylamino-5-oxo-hexanoic acid ethyl esterAusbeute 1.390,3 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
-43 °C

Versuchsvorschrift

A solution of (S)-5-oxo-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester (20 g, 10 mmol) in dry THF (150 mL) was cooled to −50° C., and then methylmagnesium bromide (31 mL, 93.28 mmol) was added dropwise at a temperature between −50 and −44° C. in 30 min. The reaction mixture was stirred at −43° C. for 2 h and placed in a freezer (ca. −20° C.) overnight. The mixture was quenched with sat. NH4Cl solution and extracted with EtOAc. The combined organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure to give the crude product, which was purified by column chromatography (8:1-3:1 petroleum ether:EtOAc) to give the title intermediate (38 g) as light yellow oil. 1H NMR (400 MHz, CDCl3): δ(ppm) 5.11-5.09 (m, 1H), 4.25-4.24 (m, 1H), 4.19 (q, J=7.2 Hz, 2H), 2.63-2.52 (m, 2H), 2.15 (s, 3H), 2.12-2.08 (m, 1H), 1.92-1.82 (m, 1H), 1.44 (s, 9H), 1.28 (t, J=7.2 Hz, 3H).

Aufarbeitung

  1. customplaced in a freezer (ca. −20° C.) overnight
  2. customThe mixture was quenched with sat. NH4Cl solution
  3. extractionextracted with EtOAc
  4. dry with materialThe combined organic layers were dried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customto give the crude product, which
  8. customwas purified by column chromatography (8:1-3:1 petroleum ether:EtOAc)

Quellen und Nachweise

ORD-Eintrag
ord-9b127c8b82c6494b94f6b8c7a3049a10
Quelldatensatz
uspto-grants-2015_12
Patentnummer
US09212168B2

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