Hydrogen Bromide → alpha-D-Glucopyranosyl bromide, tetraacetate

HRID 2112386Notes

Reaction equation

HRID 2112386 reaction equation
C(O[C@@H:5]1[O:22][C@H:21]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[C@@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:6]1[O:7][C:8](=[O:10])[CH3:9])(=O)C.C(OC(=O)C)(=O)C.[BrH:35]>C1(C)C=CC=CC=1.C(O)(=O)C.[Cl-].[Na+].O>[C:8]([O:7][C@@H:6]1[C@@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@@H:21]([CH2:23][O:24][C:25](=[O:27])[CH3:26])[O:22][C@@H:5]1[Br:35])(=[O:10])[CH3:9]

Participants

7

Reactant 3

HCID 260Hydrogen BromideHCID 7918Acetic AnhydrideHCID 2724702beta-D-Glucose pentaacetate

Product 1

HCID 101776alpha-D-Glucopyranosyl bromide, tetraacetate

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 1140TolueneSolventHCID 57417360Sodium chloride; waterSolvent

Conditions

Temperature
18 °C

Procedure

1,2,3,4,6-Penta-O-acetyl-β-D-glucopyranose (100 g, 0.251 mol) is suspended in toluene (210 ml), Acetic anhydride (9.5 ml; 0.1 mol) is added followed by hydrobromic acid 30% in acetic acid (200 ml, 1 ml). The mixture is stirred at 18° C. for 30 min. A mixture of ice water. (300 ml) and brine (100 ml) is then added with stirring. The phases are separated and the aqueous phase is extracted with toluene (100 ml). The organic phases are combined and washed with aqueous sodium hydrogencarbonate (100 ml) and brine (100 ml). Drying and evaporation of the solvent under reduced pressure yields an oil which is crystallised by addition of methyl-t-butylether (150 ml) and methylcyclohexane (300 ml). The product is isolated by filtration, washed with methylcyclohexane and dried under vacuo at 45° C.

Workup

  1. stirringwith stirring
  2. customThe phases are separated
  3. extractionthe aqueous phase is extracted with toluene (100 ml)
  4. washwashed with aqueous sodium hydrogencarbonate (100 ml) and brine (100 ml)
  5. customDrying
  6. customevaporation of the solvent under reduced pressure
  7. customyields an oil which
  8. customis crystallised by addition of methyl-t-butylether (150 ml) and methylcyclohexane (300 ml)
  9. customThe product is isolated by filtration
  10. washwashed with methylcyclohexane
  11. customdried under vacuo at 45° C.

Sources & evidence

ORD record
ord-c44a10482fdb45c3aad7bdffd9b7845d
Source dataset
uspto-grants-2009_04
Patent number
US07524822B2

Reaction notes

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