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

HRID 1486284Notes

Reaction equation

C([O:3][C:4]([C:6]1[C:7]([CH3:26])=[N:8][N:9]2[C:14]([O:15][CH2:16][C:17]3[CH:22]=[CH:21][CH:20]=[C:19]([F:23])[C:18]=3[F:24])=[CH:13][C:12]([CH3:25])=[CH:11][C:10]=12)=[O:5])C.[OH-].[Na+].CS(C)=O>O1CCOCC1>[F:24][C:18]1[C:19]([F:23])=[CH:20][CH:21]=[CH:22][C:17]=1[CH2:16][O:15][C:14]1[N:9]2[N:8]=[C:7]([CH3:26])[C:6]([C:4]([OH:5])=[O:3])=[C:10]2[CH:11]=[C:12]([CH3:25])[CH:13]=1

Participants

Conditions

Temperature: 90 °C

Procedure

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.

Workup

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

Sources & evidence

ORD record: ord-76da97ba07a24d34884e9341d050e512
Source dataset: uspto-grants-2016_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09422285B2

Reaction notes

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