Trimethylsilyl triflate → [(2R,3R,4R,5R)-3,4-diacetoxy-5-(2-bromo-5,6-dichloro-benzimidazol-1-yl)tetrahydrofuran-2-yl]methyl acetate

HRID 1900107

Reaktionsgleichung

Reaktionsgleichung von HRID 1900107
[Br:1][C:2]1[NH:3][C:4]2[CH:10]=[C:9]([Cl:11])[C:8]([Cl:12])=[CH:7][C:5]=2[N:6]=1.ClC1C(Cl)=CC2=NC(=O)N=C2C=1.C(O[C@@H:29]1[O:41][C@H:40]([CH2:42][O:43][C:44](=[O:46])[CH3:45])[C@@H:35]([O:36][C:37](=[O:39])[CH3:38])[C@H:30]1[O:31][C:32](=[O:34])[CH3:33])(=O)C.[Si](OS(C(F)(F)F)(=O)=O)(C)(C)C>CC#N.CCOC(C)=O>[Br:1][C:2]1[N:3]([C@@H:29]2[O:41][C@H:40]([CH2:42][O:43][C:44](=[O:46])[CH3:45])[C@@H:35]([O:36][C:37](=[O:39])[CH3:38])[C@H:30]2[O:31][C:32](=[O:34])[CH3:33])[C:4]2[CH:10]=[C:9]([Cl:11])[C:8]([Cl:12])=[CH:7][C:5]=2[N:6]=1

Komponenten

7

Edukt 4

HCID 65367Trimethylsilyl triflateHCID 830641,2,3,5-Tetraacetyl-beta-D-ribofuranoseHCID 4660172-bromo-5,6-dichloro-1H-benzimidazoleHCID 219664025,6-Dichlorobenzimidazol-2-one

Produkt 1

HCID 466020[(2R,3R,4R,5R)-3,4-diacetoxy-5-(2-bromo-5,6-dichloro-benzimidazol-1-yl)tetrahydrofuran-2-yl]methyl acetate

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 6342AcetonitrileLösungsmittelHCID 8857Ethyl AcetateLösungsmittel

Versuchsvorschrift

To a suspension of (7) (47.867 g, 180 mmol) in 540 mL of dry MeCN, was added 45 mL (180 mmol) of BSA. The reaction mixture was stirred at room temperature for 15 min to give a clear solution. A small amount of solid impurity remained unsilylated, believed to be 5,6-dichlorobenzimidazol-2-one from the starting material(7). 1,2,3,5-Tetra-O-acetyl-β-D-ribofuranose (60.14 g, 189 mmole) was added to this solution and then TMSOTf (38.267 mL 198 mmol) was added dropwise over 20 min. After the addition had been completed, stirring was continued at room temperature for 30 min. The reaction mixture was diluted with 2 L of EtOAc. The EtOAc solution was washed with 1:1 saturated aquenous NaHCO3 /saturated aquenous NaCl (1.5 L×2), dried (Na2SO4, 100 g), decolorized (activated charcoal, 6 g), and filtered through Celite. The filtrate was evaporated and the residue was recrystallized from MeOH to give 82.21 g (4 crops, 87%) of 52a as white needles. MP: 140°-144 ° C. This product was pure by 1H NMR.

Aufarbeitung

  1. additionwas added 45 mL (180 mmol) of BSA
  2. customto give a clear solution
  3. additionAfter the addition
  4. stirringstirring
  5. waitwas continued at room temperature for 30 min
  6. washThe EtOAc solution was washed with 1:1 saturated aquenous NaHCO3 /saturated aquenous NaCl (1.5 L×2)
  7. dry with materialdried (Na2SO4, 100 g)
  8. filtrationfiltered through Celite
  9. customThe filtrate was evaporated
  10. customthe residue was recrystallized from MeOH

Quellen und Nachweise

ORD-Eintrag
ord-a007e8559deb4b1a9bec41538400d153
Quelldatensatz
uspto-grants-1996_11
Patentnummer
US05574058

Verknüpfte Notizen

Wird geladen…