Hydrochloric Acid → 4-methoxy-6-(1-methyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyridine-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Ethyl 4-methoxy-6-(1-methyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyridine-3-carboxylate (532 mg, 1.77 mmol) was dissolved in methanol (2 ml)/1,4-dioxane (2 ml)/Water (2 ml), then 1 N aqueous sodium hydroxide (1.77 ml, 1.77 mmol) was added and the mixture was heated to 55° C. After 2 h, LCMS analysis indicated incomplete conversion. Additional 1 N aqueous sodium hydroxide (0.18 ml, 0.18 mmol) was added and the reaction mixture was stirred for 1 h. LCMS analysis indicated incomplete conversion, so additional 1 N aqueous sodium hydroxide (0.18 ml, 0.18 mmol) was added and the reaction mixture was stirred overnight at 55° C. The reaction mixture was cooled to ambient temperature and 1N HCl (2.12 ml, 2.12 mmol) was added. The mixture was concentrated to give a tan solid that was suspended in 10 mL of water, filtered, and washed with water. The solid was transferred to a flask as a slurry in methanol and concentrated to give 4-methoxy-6-(1-methyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyridine-3-carboxylic acid.

Provenance & Evidence