Tetrahydrofuran → tert-Butyl hydrogen (1,5-dihydroxypentan-2-yl)carbonimidate

HRID 1257571Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1257571
C1COCC1.[Li+].[BH4-].[C:8]([O:12][C:13]([NH:15][C@@H:16]([CH2:21][CH2:22][C:23](OC)=[O:24])[C:17](OC)=[O:18])=[O:14])([CH3:11])([CH3:10])[CH3:9]>CO>[OH:18][CH2:17][C@@H:16]([NH:15][C:13](=[O:14])[O:12][C:8]([CH3:10])([CH3:9])[CH3:11])[CH2:21][CH2:22][CH2:23][OH:24]

Komponenten

5

Edukt 3

HCID 8028Tetrahydrofuran2×HCID 2734644Dimethyl N-(tert-Butoxycarbonyl)-L-glutamateHCID 4148881Lithium borohydride

Produkt 1

HCID 2734851tert-Butyl hydrogen (1,5-dihydroxypentan-2-yl)carbonimidateAusbeute 91,7 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

A 20 L reactor was charged with 10 L of dry THF and LiBH4 (400 g) and cooled to 0° C. A THF solution of (S)-dimethyl 2-(tert-butoxycarbonylamino)pentanedioate (1000 g/3.63 mol, dissolved in 2 L of dry THF) was then added dropwise while keeping the internal temp. below 15° C. The mixture was slowly warmed to room temperature and stirred for 16 h. Cooled to 0° C., then MeOH (10 L) was added dropwise to the reaction mixture to quench the excess amount of reducing reagent. Concentrated, and the residue was poured into 5 L water. After extraction with ethyl acetate, the combined organic phase was dried over Na2SO4. After filtration the solvent was removed in vacuo to give 730 g of crude (S)-tert-butyl 1,5-dihydroxypentan-2-ylcarbamate as a pale yellow oil.

Aufarbeitung

  1. custombelow 15° C
  2. temperatureThe mixture was slowly warmed to room temperature
  3. temperatureCooled to 0° C.
  4. customto quench the excess amount of reducing reagent
  5. concentrationConcentrated
  6. additionthe residue was poured into 5 L water
  7. extractionAfter extraction with ethyl acetate
  8. dry with materialthe combined organic phase was dried over Na2SO4
  9. filtrationAfter filtration the solvent
  10. customwas removed in vacuo

Quellen und Nachweise

ORD-Eintrag
ord-e34b1d13c47d4946a7b4176add2ab383
Quelldatensatz
uspto-grants-2013_06
Patentnummer
US08461328B2

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