Toluene → 5,6-Dichloro-3-pyridinyl 2,3,4-tri-O-acetyl-5-thio-beta-D-xylopyranoside

HRID 419789Notes

Reaction equation

HRID 419789 reaction equation
C1(C)C=CC=CC=1.C(#N)C.[Cl:11][C:12]1[CH:13]=[C:14]([OH:19])[CH:15]=[N:16][C:17]=1[Cl:18].[C:20]([O:23][C@@H:24]1[C@@H:29]([O:30][C:31](=[O:33])[CH3:32])[C@H:28]([O:34][C:35](=[O:37])[CH3:36])[CH2:27][S:26][C@@H:25]1Br)(=[O:22])[CH3:21]>[Cl-].[Zn+2].[Cl-].C(N(CC)CC)C>[C:20]([O:23][C@@H:24]1[C@@H:29]([O:30][C:31](=[O:33])[CH3:32])[C@H:28]([O:34][C:35](=[O:37])[CH3:36])[CH2:27][S:26][C@H:25]1[O:19][C:14]1[CH:15]=[N:16][C:17]([Cl:18])=[C:12]([Cl:11])[CH:13]=1)(=[O:22])[CH3:21]

Participants

7

Reactant 4

HCID 1140TolueneHCID 6342AcetonitrileHCID 109263142,3,4-tri-O-acetyl-5-thio-alpha-xylopyranosyl bromideHCID 143916722,3-Dichloro-5-hydroxypyridine

Product 1

HCID 866326365,6-Dichloro-3-pyridinyl 2,3,4-tri-O-acetyl-5-thio-beta-D-xylopyranosideYield 50%

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 8471TriethylamineSolvent

Conditions

Temperature
90 °C

Procedure

5.1 g (37.5 mM) of zinc chloride are melted under reduced pressure, the melt is cooled under an inert atmosphere and then 12 ml of toluene, 12 ml of acetonitrile, 3 g of 4 Å molecular sieve and 2.45 g (15 mM) of 5,6-dichloro-3-pyridinol are added. The temperature of the mixture is brought to 90° C. and 3.78 g (37.5 mM) of triethylamine and 5.86 g (16.5 mM) of 2,3,4-tri-O-acetyl-5-thio-α-D-xylopyranosyl bromide are added. The reaction medium is stirred at 90° C. for 20 minutes and is then cooled and filtered to remove the inorganic salts, which are washed with ethyl acetate. The combined organic phases are washed with a 0.5 N sodium hydroxide solution and then the pH is brought to a value of 3 using a 0.1 N hydrochloric acid solution. The organic phase is subsequently washed with a saturated sodium chloride solution, dried over magnesium sulfate and concentrated under reduced pressure. The product is crystallized from ethyl ether and the desired product is obtained in the form of a light brown solid with a yield of 50%.

Workup

  1. temperaturethe melt is cooled under an inert atmosphere
  2. customis brought to 90° C.
  3. temperatureis then cooled
  4. filtrationfiltered
  5. customto remove the inorganic salts, which
  6. washare washed with ethyl acetate
  7. washThe combined organic phases are washed with a 0.5 N sodium hydroxide solution
  8. washThe organic phase is subsequently washed with a saturated sodium chloride solution
  9. dry with materialdried over magnesium sulfate
  10. concentrationconcentrated under reduced pressure
  11. customThe product is crystallized from ethyl ether

Sources & evidence

ORD record
ord-02d5718720d647dc93b5c7e15990e4d6
Source dataset
uspto-grants-2012_01
Patent number
US08093394B2

Reaction notes

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