89202-89-1

68809-65-4

89202-89-1

Ethyl 1,4-dimethyl-1H-pyrazole-3-carboxylate (440 mg, 2.62 mmol) was added to 1N aqueous sodium hydroxide (3 mL, 3 mmol) and ethanol (3 mL), and the reaction was carried out according to the same method as in Example 20 of the reference to obtain pale yellow crystalline 1,4-dimethyl-1H-pyrazole-3-carboxylic acid (152 mg, 41% yield). The product was characterized by 1H-NMR (CDCl3, 300 MHz): δ 2.30 (3H, s), 3.92 (3H, s), 7.21 (1H, s).