Sodium Hydroxide → 5-(2,4-Dichlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2-acetic acid
Reaktionsgleichung
[OH-].[Na+].[Cl:3][C:4]1[CH:24]=[C:23]([Cl:25])[CH:22]=[CH:21][C:5]=1[C:6]([C:8]1[N:12]([CH3:13])[C:11]([CH2:14][C:15]([O:17]CC)=[O:16])=[CH:10][C:9]=1[CH3:20])=[O:7]>>[Cl:3][C:4]1[CH:24]=[C:23]([Cl:25])[CH:22]=[CH:21][C:5]=1[C:6]([C:8]1[N:12]([CH3:13])[C:11]([CH2:14][C:15]([OH:17])=[O:16])=[CH:10][C:9]=1[CH3:20])=[O:7]Komponenten
3
Versuchsvorschrift
A solution of 2.38 mL (1.1 eq) of 1N NaOH was added dropwise to a refluxing solution of 76.89 g (0.217 mole) of ethyl 5-(2,4-dichlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2-acetat (3)in 750 mL absolute ethanol. The mixture was heated under reflux for 20 minutes. The reaction was poured into 3N HCl/ice and extracted three times with diethyl ether. The organics were washed with water (twice), brine, and dried (MgSO4). Evaporation of the solvent in vacuo gave a tan oil which was crystallized from acetonitrile to give 63.05 g of product: mp 140°-143° C.; mass spectrum (Cl--CH4) m/z=326 (M+1); NMR 300 MHz (Me2SO-d6) d 7.8 (s, 1H); 7.6 (m, 1H); 7.4 (m, 1H); 6.0 (s, 1H); 3.8 (s, 3H); 3.75 (s, 2H); 1.45 (s, 3H). Anal Calcd for C15H13Cl2NO3 : C, 55.24; H, 4.02; N, 4.29. Found: C, 55.47; H, 3.84; N, 4.29.