Imidazole → (2S,3R)-2-tert-Butoxycarbonylamino-3-(tert-butyl-diphenyl-silanyloxy)-butyric acid methyl ester

HRID 2285379Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2285379
[CH3:1][O:2][C:3](=[O:16])[C@@H:4]([NH:8][C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[C@H:5]([OH:7])[CH3:6].[C:17]([Si:21](Cl)([C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)([CH3:20])([CH3:19])[CH3:18].N1C=CN=C1>CN(C)C=O.O>[CH3:1][O:2][C:3](=[O:16])[C@@H:4]([NH:8][C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[C@H:5]([O:7][Si:21]([C:17]([CH3:20])([CH3:19])[CH3:18])([C:28]1[CH:29]=[CH:30][CH:31]=[CH:32][CH:33]=1)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[CH3:6]

Komponenten

6

Edukt 3

HCID 795ImidazoleHCID 94078tert-ButyldiphenylchlorosilaneHCID 11368286Methyl N-(tert-butoxycarbonyl)-L-threoninate

Produkt 1

HCID 10719205(2S,3R)-2-tert-Butoxycarbonylamino-3-(tert-butyl-diphenyl-silanyloxy)-butyric acid methyl esterAusbeute 95,2 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 962WaterLösungsmittelHCID 6228DimethylformamideLösungsmittel

Versuchsvorschrift

(2S,3R)-2-tert-Butoxycarbonylamino-3-hydroxy-butyric acid methyl ester (1.85 g, 7.93 mmol) was dissolved in N,N-dimethylformamide (10 mL), under an atmosphere of nitrogen. tert-Butyl(chloro)diphenylsilane (2.89 mL, 11.1 mmol) was added followed by imidazole (1.08 g, 15.9 mmol) and the reaction was left to stir for 72 h. The reaction mixture was diluted with water and then extracted with ethyl acetate. The combined organics were dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography using a stepwise gradient iso-hexanes/ethyl acetate from 1:0 to 4:1 to afford the title compound (3.56 g, 95%) as a pale Greene oil. 1H NMR (300 MHz, CDCl3) δ 0.89 (d, J=6.6 Hz, 3H), 1.04 (s, 9H), 1.10 (s, 9H), 3.64 (s, 3H), 4.18-4.26 (m, 1H), 4.39-4.50 (m, 1H), 5.34 (d, J=9.9 Hz, 1H), 7.36-7.50 (m, 6H), 7.60-7.69 (m, 2H), 7.71-7.77 (m, 2H). LCMS (m/z) 472.2 [M+H], Tr=4.13 min.

Aufarbeitung

  1. waitthe reaction was left
  2. extractionextracted with ethyl acetate
  3. dry with materialThe combined organics were dried over anhydrous sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customThe residue was purified by silica gel chromatography

Quellen und Nachweise

ORD-Eintrag
ord-f2a849630455456bb9101ab5234addcb
Quelldatensatz
uspto-grants-2015_09
Patentnummer
US09145441B2

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