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ChemicalBook CAS DataBase List 5-Formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid
253870-02-9

5-Formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid synthesis

9synthesis methods
2,4-Dimethyl-5-aldehyde-1H-pyrrole-3-carboxylic acid is a yellow crystalline substance, mainly used for pharmaceutical intermediates. It is synthesized by the hydrolysis of Ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate with potassium hydroxide in methanol.
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Yield:253870-02-9 93%

Reaction Conditions:

with potassium hydroxide in methanol;water

Steps:

1.2 Step 2
Step 2 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).

References:

SUGEN, INC. US2003/92917, 2003, A1

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