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

HRID 1155297Notes

Reaction equation

HRID 1155297 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); δ 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-d8100fe71ede450cbdd8c141a29adfae
Source dataset
uspto-grants-1981_11
Patent number
US04301152

Reaction notes

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