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

HRID 1486242Notes

Reaction equation

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

Participants

Conditions

Temperature: 90 °C

Procedure

700 mg (1.81 mmol) of ethyl 2,5-dimethyl-7-[(2,3,6-trifluorobenzyl)oxy]pyrazolo[1,5-a]pyridine-3-carboxylate from Example 9A were initially charged in 18 ml of dioxane and heated to 90° C. 4.5 ml of dioxane and 7.25 ml (14.50 mmol) of 2 N aqueous sodium hydroxide solution were added, and the reaction mixture was stirred at 90° C. for two days. Another 3.63 ml (7.26 mmol) of 2 N aqueous sodium hydroxide solution were added and the mixture was stirred at 90° C. for a further 2 hours. The reaction solution was admixed with 15 ml of 1 N aqueous hydrochloric acid and stirred for 30 min. In the course of this, solids precipitated out. This suspension was filtered, and the solids filtered off were washed with a little water and dried under high vacuum. 358 mg of the target compound were obtained (54% of theory).

Workup

stirringthe mixture was stirred at 90° C. for a further 2 hours
stirringstirred for 30 min
customIn the course of this, solids precipitated out
filtrationThis suspension was filtered
filtrationthe solids filtered off
washwere washed with a little water
customdried under high vacuum

Sources & evidence

ORD record: ord-3fb8a36956fe4c0e886dba200e01f033
Source dataset: uspto-grants-2016_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09422285B2

Reaction notes

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