[Na].Cl.[CH3:3][O:4][C:5](=[O:8])[CH2:6][NH2:7].Cl([O-])(=O)(=O)=O.CN(C)[CH:16]=[C:17]([C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[CH:18]=[N+](C)C.[CH2:29](O)C>>[C:22]1([C:17]2[CH:16]=[C:6]([C:5]([O:4][CH2:3][CH3:29])=[O:8])[NH:7][CH:18]=2)[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1Sodium metal (900 mg, 41.0 mmol) was added to dry ethanol (150 mL) and allowed to dissolve over 30 min. Glycine methyl ester hydrochloride (3.2 g, 25.0 mmol) and (3-dimethylamino-2-phenyl-prop-2-enylidene)-dimethyl-ammonium perchlorate (5.0 g, 16.0 mmol) were added successively and the reaction mixture heated at reflux for 16 h. Ethanol was evaporated in vacuo, the residue diluted with water and extracted with chloroform. The organic layer was washed with water, brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude product obtained was purified by column chromatography over neutral alumina using 10% ethyl acetate in petroleum ether as eluent to afford ethyl 4-phenyl-1H-pyrrole-2-carboxylate (2.0 g, 57%) as a solid.
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