Dimethyl Sulfoxide → 7-[(2,3-Difluorobenzyl)oxy]-2,5-dimethylpyrazolo[1,5-a]pyridine-3-carboxylic Acid

Temperature

90 °C

A solution of 190 mg (0.527 mmol) of 7-[(2,3-difluorobenzyl)oxy]-2,5-dimethylpyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester from Example 116A in 5 ml of dioxane was admixed with 2.1 ml of 2 N sodium hydroxide solution. The resulting mixture was stirred at 90° C. for 15 h. Owing to incomplete mixing, 1 ml of dimethyl sulphoxide was added, followed by further 2 N sodium hydroxide solution (1 ml). The resulting mixture was stirred for a further 2 h. After the reaction had ended, the solvent was removed under reduced pressure. The residue was admixed with acetonitrile (5 ml), followed by the dropwise addition of trifluoroacetic acid (2 ml). The resulting precipitate was filtered off and dried under reduced pressure, which gave 130 mg (71% of theory, 93% pure) of the target compound.

1. stirringThe resulting mixture was stirred for a further 2 h
2. customthe solvent was removed under reduced pressure
3. additionfollowed by the dropwise addition of trifluoroacetic acid (2 ml)
4. filtrationThe resulting precipitate was filtered off
5. customdried under reduced pressure, which
6. customgave 130 mg (71% of theory, 93% pure) of the target compound

ORD record

ord-76da97ba07a24d34884e9341d050e512

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422285B2