Sodium Hydroxide → 6-(4-Tert-butyl-phenyl)-4-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid

HRID 2272954Notes

Reaction equation

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

Participants

Conditions

Temperature: 100 °C

Procedure

A solution of 547 mg (1.61 mmol) 6-(4-tert-butyl-phenyl)-4-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester in 10 ml 1,2-dimethoxyethane is treated with 5 ml 1 N aqueous NaOH solution. The resulting suspension is heated to 100° C. and the resulting solution is stirred at this temperature for 48 hours. The reaction mixture is cooled to room temperature and evaporated. The residue is triturated with water and the solids are filtered off and washed with water. The filtrate is acidified with 2 N HCl. The resulting precipitate is filtered off, washed with 2 N HCl and with water and dried under vacuum to give 6-(4-tert-butyl-phenyl)-4-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid as colourless solid; HPLC/MS 2.03 (A), [M+H] 312.

Workup

temperatureThe reaction mixture is cooled to room temperature
customevaporated
customThe residue is triturated with water
filtrationthe solids are filtered off
washwashed with water
filtrationThe resulting precipitate is filtered off
washwashed with 2 N HCl and with water
customdried under vacuum

Sources & evidence

ORD record: ord-a465ef600bf84b749356f93286087419
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09120805B2

Reaction notes

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