Ammonia → Methyl 1-(2-amino-2-oxoethyl)-2,5-dihydro-4-hydroxy-2-oxo-1H-pyrrole-3-carboxylate
Reaktionsgleichung
C[O:2][C:3](=O)[CH2:4][N:5]1[CH2:9][C:8]([OH:10])=[C:7]([C:11]([O:13][CH3:14])=[O:12])[C:6]1=[O:15].[NH3:17]>>[OH:10][C:8]1[CH2:9][N:5]([CH2:4][C:3]([NH2:17])=[O:2])[C:6](=[O:15])[C:7]=1[C:11]([O:13][CH3:14])=[O:12]Komponenten
3
Versuchsvorschrift
23 g (0.1 mol) of the 2,5-dihydro-4-hydroxy-3-methoxycarbonyl-2-oxo-1H-pyrrole-1-acetic acid methyl ester described in Example 1 are dissolved in 200 ml of a concentrated aqueous ammonia solution and stirred at room temperature for 12 hours. The yellowish solution is then concentrated to dryness by evaporation under a water-jet vacuum. The resulting solid residue is dissolved in 200 ml of water, and a concentrated aqueous solution of hydrochloric acid is added until a strongly acidic reaction takes place. The resulting colourless precipitate is filtered off, washed with water and acetone and dried at 50° under reduced pressure. 2,5-dihydro-4-hydroxy-3-methoxycarbonyl-2-oxo-1H-pyrrole-1-acetamide is obtained in the form of white crystals having a melting point of 202° (decomposition).