Potassium Hydroxide → 4-Ethoxy-2-methyl-2H-pyrazolo[3,4-b]pyridine-5-carboxylic acid

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Reaction Steps

28.5 g. of 4-ethoxy-2 -methyl-2H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester, hydrochloride from Example 2 and 15 g. of potassium hydroxide are refluxed in 100 ml. of ethanol for 10 hours. The solvent is then distilled off and the residue is dissolved in 20 ml. of water. Acetic acid is added and a precipitate of 16 g. of 4-ethoxy-2-methyl-2H-pyrazolo[3,4-b]pyridine-5-carboxylic acid; m.p. 222°-225° (DMF); is obtained.

Provenance & Evidence