Carbon Dioxide → HCID 21071901, compound

HRID 1372417Notes

Reaction equation

C(OC([C:6]1[NH:7][C:8]([CH3:21])=[C:9]([C:12]2[CH:17]=[CH:16][C:15]([C:18]([OH:20])=[O:19])=[CH:14][CH:13]=2)[C:10]=1[CH3:11])=O)C.[OH-].[K+].Cl.C(=O)=O>C(OCC)(=O)C.CCCCCC.C(O)(=O)C.O.C(O)CO>[CH3:21][C:8]1[NH:7][CH:6]=[C:10]([CH3:11])[C:9]=1[C:12]1[CH:17]=[CH:16][C:15]([C:18]([OH:20])=[O:19])=[CH:14][CH:13]=1

Participants

Conditions

Temperature: 98 °C

Procedure

4-(4-Carboxy-phenyl)-3,5-dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester (11.8 g), 11.8 mL of ethylene glycol, 36 mL of water and 13.6 mL of 9 N potassium hydroxide were refluxed at 105° C. for 25 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 to 98° C. and 13 mL of 10 N hydrochloric acid was added to a pH of 2.0 accompanied by rapid release of carbon dioxide gas. The maximum temperature reached was 103° C. which dropped to 95° C. by the end of the gas evolution. The mixture was cooled in an ice bath 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 8.7 g (99% yield) of 4-(2,4-dimethyl-1H-pyrrol-3-yl)-benzoic acid as a light purple solid. 1H-NMR (dimethylsulfoxide-d6) δ 2.00, 2.18 (2×s, 2×3H, 2×CH3), 6.46 (s, 1H, pyrrole CH), 7.34, 7.90 (multiplets, 4H, aromatic), 10.49 (br s, 1H, NH), 12.70 (br s, 1H, COOH). MS m/z 216 [M+1].

Workup

customreached was 103° C.
additiondropped to 95° C. by the end of the gas evolution
temperatureThe mixture was cooled in an ice bath
filtrationThe solids were collected by vacuum filtration
washwashed three times with 20 mL of water each time

Sources & evidence

ORD record: ord-c30ea6a2f9c346429292dcb3faa8b4db
Source dataset: uspto-grants-2007_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07157577B2

Reaction notes

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