5952-92-1

ChEBI: 1-methyl-pyrazole-4-carboxylic acid is a member of the class of pyrazoles that is N-methylpyrazole substituted by a carboxy group at position 4. It has a role as a metabolite. It is a member of pyrazoles and a monocarboxylic acid. It is functionally related to a N-methylpyrazole.

General procedure for the synthesis of 1-methyl-1H-pyrazole-4-carboxylic acid from ethyl 1-methyl-1H-pyrazole-4-carboxylate: 1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (20.2 g, 131 mmol) and sodium hydroxide (6.3 g, 158 mmol) were dissolved in 200 mL of anhydrous ethanol and heated to reflux for 2 h. The stirring process was continued at room temperature for the subsequent 18 hour. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was dissolved in water and the aqueous solution was washed with ether and subsequently acidified with concentrated hydrochloric acid. The precipitated solid was collected, filtered, washed with water and dried in air to give 14.2 g of 1-methyl-1H-pyrazole-4-carboxylic acid in 86% yield.

[1] Patent: US5498630, 1996, A
[2] Patent: US2004/14766, 2004, A1
[3] Patent: US2004/14766, 2004, A1
[4] Patent: WO2003/106459, 2003, A1. Location in patent: Page 116; 156