Hydrogen Bromide → HCID 86632424, compound

HRID 2100235Notes

Reaction equation

HRID 2100235 reaction equation
[BrH:1].[N:2]([CH2:5][C@H:6]1[O:15][CH:10](OC(=O)C)[C@H:9]([O:16][C:17](=[O:19])[CH3:18])[C@@H:8]([O:20][C:21](=[O:23])[CH3:22])[C@H:7]1[O:24][C:25](=[O:27])[CH3:26])=[N+:3]=[N-:4].C(OCC)(=O)C>C(O)(=O)C.C(Cl)Cl>[C:17]([O:16][C@@H:9]1[C@@H:8]([O:20][C:21](=[O:23])[CH3:22])[C@@H:7]([O:24][C:25](=[O:27])[CH3:26])[C@@H:6]([CH2:5][N:2]=[N+:3]=[N-:4])[O:15][C@@H:10]1[Br:1])(=[O:19])[CH3:18]

Participants

6

Reactant 3

HCID 260Hydrogen BromideHCID 8857Ethyl AcetateHCID 56619630HCID 56619630, compound

Product 1

HCID 86632424HCID 86632424, compound

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

Hydrogen bromide (2 mL of a 30% solution in acetic acid) was added to a solution of 6-azido-6-deoxy-1,2,3,4-tetra-O-acetyl-galactopyranose 36 (α:β, 0.8:1) (320 mg, 0.86 mmol) in anhydrous DCM (10 mL). The mixture was stirred under argon at 0° C. After 1¾h, t.1.c. (petrol:ethyl acetate, 2:1) indicated the formation of two products (Rf 0.5, 0.2) with some remaining starting material (Rf 0.3). The reaction mixture was quenched with ice/water (30 mL), diluted with DCM (40 mL), neutralized with sodium bicarbonate (2×40 mL), washed with brine (40 mL), dried (MgSO4), filtered and concentrated in vacuo to yield 350 mg of crude product, which was used without further purification, but a small portion was retained and purified by flash column chromatography (DCM:ether, 60:1) to afford 2,3,4-tri-O-acetyl-6-azido-6-deoxy-α-D-galactopyranosylbromide 37 as a white solid Rf 0.5 (60:1, DCM:ether); m.p. 81.5-82.2C (ether/petrol) [Lit. 82-83° C. (ether/petrol) Jezo, I. and Zemek, J., Chemicke Zvesti, 33, 533-541 (1979)]; [α]D25+70.8 (c, 1.7 in CHCl3) [Lit. [α]D22 +133.8 (c, 1 in CHCl3)], νmax (thin film) 2107 (sh, N3), 1750 (st, C═O)cm−1; δH (400 MHz, CDCl3) 2.03, 2.12, 2,18 (9H, 3 x s, 3 x CH3), 3.30-3.40 (2H, m, H-6, H-6′), 4.47 (1H, t, H-5), 5.04 (1H, dd, J1,2 4.0, J2,3 10.7, H-2), 5.43 (1H, dd, J3,4 3.2, H-3), 5.69 (1H, m, H-4), 6.69 (1H, d, H-1).

Workup

  1. customThe reaction mixture was quenched with ice/water (30 mL)
  2. additiondiluted with DCM (40 mL)
  3. washwashed with brine (40 mL)
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customto yield 350 mg of crude product, which
  8. customwas used without further purification
  9. custompurified by flash column chromatography (DCM:ether, 60:1)

Sources & evidence

ORD record
ord-abb86c9957d64d17b6df61d0715f0a6d
Source dataset
uspto-grants-2009_08
Patent number
US07572604B2

Reaction notes

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