Hydrochloric Acid → 2-Cyclopropyl-5-methyl-7-[(2,3,6-trifluorobenzyl)oxy]pyrazolo[1,5-a]pyridine-3-carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

A solution of 462 mg (1.01 mmol; purity 85%) of methyl 2-cyclopropyl-5-methyl-7-[(2,3,6-trifluorobenzyl)oxy]pyrazolo[1,5-a]pyridine-3-carboxylate from Example 156A in 10.5 ml of dioxane and 3 ml of DMSO was admixed with 5.55 ml (11.10 mmol) of 2 N sodium hydroxide solution, and the mixture was stirred at 100° C. for 6.5 h. Another 1 ml (2 mmol) of 2 N sodium hydroxide solution was added and the mixture was stirred at 100° C. for a further 2.5 h. The reaction solution was cooled down to 0° C. and adjusted to pH 2 with 1 N hydrochloric acid. The solids that precipitated out were stirred for 30 min, filtered off and dried under high vacuum. 300 mg of the title compound were obtained (74% of theory, 93% purity) and were converted without further purification.

Provenance & Evidence