Benzyl Bromide → HCID 53782419, compound

HRID 2399555Notes

Reaction equation

HRID 2399555 reaction equation
C1(NC([O:10][C@H:11]2[C@H:18]([OH:19])[CH2:17][O:16][C@@H:13]([O:14][CH3:15])[C@@H:12]2[OH:20])=O)C=CC=CC=1.[H-].[Na+].[CH2:23](Br)[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1>CN(C=O)C>[CH2:23]([O:20][C@@H:12]1[C@@H:11]([OH:10])[C@H:18]([O:19][CH2:23][C:24]2[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=2)[CH2:17][O:16][C@H:13]1[O:14][CH3:15])[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 86748972HCID 86748972, compound

Product 1

HCID 53782419HCID 53782419, compoundYield 90%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of methyl 3-O-phenylcarbamoyl-b-D-xylopyranoside (73.6 g, 0.26 mole) in DMF (300 ml) was added by portions 60% NaH in oil (36.0 g, 0.9 mole). After stirring at room temperature for 30 min, benzyl bromide (113 ml, 0.95 mole) was added dropwise to the reaction mixture. After the addition was completed, the stirring was continued for 3 hr. The reaction mixture was evaporated under reduced pressure, and the oily residue was partitioned between ether (500 ml) and water (500 ml). The ether layer was dried over anhydrous sodium sulfate, evaporated to dryness under reduced pressure. The resulting amber viscous oil (150 g) was dissolved in 28% NaOMe--MeOH (750 ml) and heated under reflux for 19 hrs. The reaction mixture was evaporated to dryness under reduced pressure. The oily residue was partitioned between ether (500 ml) and water (500 ml). The ether layer was washed with water (250 ml×2), and evaporated to dryness under reduced pressure. The residue was chromatographed on silica gel using CH2Cl2 /AcOEt (95:5) as an eluent to give methyl 2,4-di-O-benzyl-b-D-xylopyranoside (80.5 g, 90% yield) as amorphous powder; EI-MS: m/z 344 (M+); 1H-NMR (CDCl3)d: 2.54 (1H,d,J=2.5 Hz), 3.21 (1H,dd,J=7.5 & 9 Hz), 3.22 (1H,dd,J=10 & 12 Hz), 3.52 (3H,s), 3.49 (1H,m), 3.68 (1H,t,J=9 Hz), 3.93 (1H,dd,J=6 & 12 Hz), 4.25 (1H,d,J=7.5 Hz), 4.63 (1H,d,J=12 Hz), 4.66 (1H,d,J=11.5 Hz), 4.75 (1H,d,J=12 Hz), 4.90 (1H,d,J=12 Hz), 7.31 (10H, br.s).

Workup

  1. additionAfter the addition
  2. waitthe stirring was continued for 3 hr
  3. customThe reaction mixture was evaporated under reduced pressure
  4. customthe oily residue was partitioned between ether (500 ml) and water (500 ml)
  5. dry with materialThe ether layer was dried over anhydrous sodium sulfate
  6. customevaporated to dryness under reduced pressure
  7. dissolutionThe resulting amber viscous oil (150 g) was dissolved in 28% NaOMe--MeOH (750 ml)
  8. temperatureheated
  9. temperatureunder reflux for 19 hrs
  10. customThe reaction mixture was evaporated to dryness under reduced pressure
  11. customThe oily residue was partitioned between ether (500 ml) and water (500 ml)
  12. washThe ether layer was washed with water (250 ml×2)
  13. customevaporated to dryness under reduced pressure
  14. customThe residue was chromatographed on silica gel

Sources & evidence

ORD record
ord-938e62457de4466a80050024f2d3b1cf
Source dataset
uspto-grants-1995_09
Patent number
US05449785

Reaction notes

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