Reaktion #87167

Reaktionsgleichung

SOCl2

methanol

1-(2,4-dimethoxybenzyl)-5-oxopyrrolidine-3-carboxylic acid

→

methyl 1-(2,4-dimethoxybenzyl)-5-oxopyrrolidine-3-carboxylate

Ausbeute 81.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturunder reflux for 7 h
3. 3
   TemperaturThe mixture was cooled to ambient temperature
4. 4
   Einengenconcentrated
5. 5
   SonstigeThe residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=6:1 to 2:1)

Vorschrift

SOCl2 (6.4 g, 54 mmol) was added dropwise to methanol (40 mL) followed by addition of 1-(2,4-dimethoxybenzyl)-5-oxopyrrolidine-3-carboxylic acid (5.0 g, 18 mmol) at 0° C. The reaction mixture was stirred at ambient temperature for 1 h and then heated under reflux for 7 h. The mixture was cooled to ambient temperature and concentrated. The residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=6:1 to 2:1) to afford methyl 1-(2,4-dimethoxybenzyl)-5-oxopyrrolidine-3-carboxylate (a mixture of two enantiomers, 4.3 g, 81% yield) as a colorless oil. The two enantiomers were separated by chiral prep-HPLC.

Quelle