Reaktion #2061640

Reaktionsgleichung

dimethyl 5-formylpyridine-2,3-dicarboxylate

ethanedithiol

para-toluenesulfonic acid

→

title compound

Ausbeute 67.0%

Dimethyl 5-(1,3-dithiolan-2-yl)-2,3-pyridinedicarboxylate

Ausbeute 67.0%

Lösungsmittel

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux for 5.5 hours
2. 2
   SonstigeDuring this time, water is removed by placement of an addition funnel
3. 3
   workup.ADDITIONcontaining 3 angstrom molecular sieves in between the reaction flask
4. 4
   TemperaturAfter cooling
5. 5
   workup.ADDITIONthe reaction is diluted with methylene chloride (20 mL)
6. 6
   Waschenis washed with 10% aqueous sodium carbonate and saturated sodium chloride solutions
7. 7
   TrocknenThe organic solution is dried over anhydrous magnesium sulfate
8. 8
   Einengenconcentrated in vacuo
9. 9
   Sonstigeto give a residue
10. 10
    SonstigeThe residue is purified by chromatography

Vorschrift

A solution of dimethyl 5-formylpyridine-2,3-dicarboxylate (0.73 g, 0.00327 mol), ethanedithiol (0.357 mL, 0.00425 mol) and a catalytic amount of para-toluenesulfonic acid in chloroform (20 mL) is heated at reflux for 5.5 hours. During this time, water is removed by placement of an addition funnel containing 3 angstrom molecular sieves in between the reaction flask and the reflux condensor. After cooling, the reaction is diluted with methylene chloride (20 mL) and is washed with 10% aqueous sodium carbonate and saturated sodium chloride solutions. The organic solution is dried over anhydrous magnesium sulfate and concentrated in vacuo to give a residue. The residue is purified by chromatography using silica gel and 33% ethyl acetate in hexanes as eluant to yield the title compound as a clear oil (0.66 g, 67%), identified by IR and NMR spectral analyses.

Quelle