Acetic Acid → 2,3,4-Tri-O-acetyl-6-deoxy-6-phthalimido-alpha-D-galactopyranosyl bromide

HRID 1105875Notes

Reaction equation

HRID 1105875 reaction equation
C(O[C:5]1([N:24]2[C:28](=[O:29])[C:27]3=[CH:30][CH:31]=[CH:32][CH:33]=[C:26]3[C:25]2=[O:34])O[C@H](C)[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)[CH3:9])(=O)C.[BrH:35].[C:36]([OH:39])(=[O:38])[CH3:37]>ClCCl>[C:36]([O:39][C@@H:9]1[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]([CH2:5][N:24]2[C:25](=[O:34])[C:26]3=[CH:33][CH:32]=[CH:31][CH:30]=[C:27]3[C:28]2=[O:29])[O:7][C@@H:8]1[Br:35])(=[O:38])[CH3:37]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 260Hydrogen BromideHCID 542334551,2,3,4-tetra-O-acetyl-6-deoxy-phthalimido-D-galactopyranose

Product 1

HCID 541665552,3,4-Tri-O-acetyl-6-deoxy-6-phthalimido-alpha-D-galactopyranosyl bromideYield 91%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of 1,2,3,4-tetra-O-acetyl-6-deoxy-phthalimido-D-galactopyranose (4.2 g.) in dichloromethane (2 ml.) is treated with 30-32% hydrobromic acid in glacial acetic acid (10 ml.) for 1 hour. The reaction mixture is poured into ice-water, and the product is immediately extracted with dichloromethane. The organic layer is washed with cold aqueous sodium hydrogencarbonate and cold water, dried, and evaporated in vacuo to give the title compound as a syrup (4.0 g., 91%); n.m.r. (chloroform-d): ∂ 6.63 (d, J1,2 4.0 Hz, H-1), 7.58-7.90 (4 aromatic), 1.96, 2.07 and 2.13 (3 OAc).

Workup

  1. extractionthe product is immediately extracted with dichloromethane
  2. washThe organic layer is washed with cold aqueous sodium hydrogencarbonate and cold water
  3. customdried
  4. customevaporated in vacuo

Sources & evidence

ORD record
ord-4a533c16343a422c9a9e31a6962be18d
Source dataset
uspto-grants-1982_01
Patent number
US04310505

Reaction notes

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