Carbon Dioxide → HCID 21071889, compound

Participants

Reaction Conditions

Reaction Steps

4-(3-Carboxy-phenyl)-3,5-dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester (15.0 g), 15 mL of ethylene glycol, 45 mL of water and 17.4 mL of 9 N potassium hydroxide were refluxed at 105° C. for 30 minutes. Thin layer chromatography (ethyl acetate:hexane:acetic acid 4:6:0.5) showed conversion of all starting material at Rf 0.5 to a new product at Rf 0.3. The mixture was cooled 100° C. and 21 mL of 10 N hydrochloric acid were added to a pH of 2.5 accompanied by rapid release of carbon dioxide gas. The mixture was cooled to ambient temperature and vigorously stirred for 30 minutes. The solids were collected by vacuum filtration and washed three times with 20 mL of water each time to give 10.9 g (97% yield) of 3-(2,4-dimethyl-1H-pyrrol-3-yl)-benzoic acid as a light purple solid. 1H-NMR (dimethylsulfoxide-d6) δ 2.08, 2.16 (2×s, 2×3H, 2×CH3), 6.45 (s, 1H, pyrrole CH), 7.46, 7.75 (multiplets, 4H, aromatic), 10.42 (br s, 1H, NH), 12.81 (br s, 1H, COOH). MS m/z 216 [M+1].

Provenance & Evidence