Hydrochloric Acid → methyl (2S)-2-isocyanato-3,3-dimethylbutanoate

HRID 1511559Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1511559
Cl.[CH3:2][C:3]([CH3:11])([CH3:10])[C@@H:4]([C:6]([O:8][CH3:9])=[O:7])[NH2:5].N1C=CC=CC=1.[C:18](Cl)(Cl)=[O:19].Cl>C(Cl)Cl>[CH3:2][C:3]([CH3:11])([CH3:10])[C@@H:4]([C:6]([O:8][CH3:9])=[O:7])[N:5]=[C:18]=[O:19]

Komponenten

6

Edukt 4

HCID 313Hydrochloric AcidHCID 1049PyridineHCID 6371PhosgeneHCID 16217630Methyl L-tert-leucinate hydrochloride

Produkt 1

HCID 59856496methyl (2S)-2-isocyanato-3,3-dimethylbutanoateAusbeute 74 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

A solution of methyl 3-methyl-L-valinate hydrochloride (10.0 g, 54.9 mmol) and pyridine (22.3 mL, 276 mmol) in methylenechloride (300 mL) was cooled in an ice bath under nitrogen. Phosgene (20% in toluene, 41.1 mL, 83.0 mmol) was added dropwise over 0.5 h using an addition funnel. The resulting mixture was stirred 1 h then poured into cold 1M hydrochloric acid and extracted with methylenechloride (3×100 mL). The combined organic extracts were washed with brine, dried with anhydrous magnesium sulfate, filtered and concentrated. Flash column chromatography eluting with hexane/ethyl acetate 90/10 gave methyl 3-methyl-N-(oxomethylene)-L-valinate as an orange oil, 6.99 g (74% yield).

Aufarbeitung

  1. extractionextracted with methylenechloride (3×100 mL)
  2. washThe combined organic extracts were washed with brine
  3. dry with materialdried with anhydrous magnesium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated
  6. washFlash column chromatography eluting with hexane/ethyl acetate 90/10

Quellen und Nachweise

ORD-Eintrag
ord-8e9b55b81c9a4384a8888d505934c745
Quelldatensatz
uspto-grants-2012_07
Patentnummer
US08216999B2

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