Hydrochloric Acid → 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic Acid

Participants

Reaction Steps

5-Formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester (2 g, 10 mmol) was added to a solution of potassium hydroxide (3 g, 53 mmol) dissolved in methanol (3 mL) and water (10 mL). The mixture was refluxed for 3 hours, cooled to room temperature and acidified with 6 N hydrochloric acid to pH 3. The solid was collected by filtration, washed with water and dried in a vacuum oven overnight to give 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (1.6 g, 93%). 1H NMR (300 MHz, DMSO-d6) δ 12.09 (s, br, 2H, NH & COOH), 9.59 (s, 1H, CHO), 2.44 (s, 3H, CH3), 2.40 (s, 3H, CH3).

Provenance & Evidence