Reaktion #412596

Reaktionsgleichung

Ethyl 5-chlorocarbonyl-1,4 dimethylpyrrole-2-acetate

pyridine

ethanol

→

ethyl-1,4 dimethyl-5-ethoxycarbonylpyrrole-2-acetate

Ausbeute 87.0%

Lösungsmittel

Ether

ether

methylene chloride ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   workup.STIRRINGStirring
3. 3
   Sonstigeare removed by filtration
4. 4
   WaschenThe organic solution is washed with aqueous 1 N HCl (2×100 ml)
5. 5
   Trocknenbrine (100 ml), and the ether layer is dried with magnesium sulfate
6. 6
   SonstigeThe solvent is then removed

Vorschrift

Ethyl 5-chlorocarbonyl-1,4 dimethylpyrrole-2-acetate (29.3 g, 0.12 mol, prepared acc. to U.S. Pat. No. 3,950,355) is dissolved in 150 ml of 1:1 methylene chloride/ether and added over 10 minutes to a solution of pyridine (15 ml) and absolute ethanol (20 ml) in ether (100 ml) with stirring. After addition is complete, 4-N,N-dimethylaminopyridine (300 mg) is added. Stirring is continued for three hours. Ether (250 ml) is then added and deposited solids are removed by filtration. The organic solution is washed with aqueous 1 N HCl (2×100 ml), then brine (100 ml), and the ether layer is dried with magnesium sulfate. The solvent is then removed to give 26.3 g (87%) of ethyl-1,4 dimethyl-5-ethoxycarbonylpyrrole-2-acetate as a low melting red solid.

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