Lithium Hydroxide → 5-tert-Butyl-2-p-tolyl-2H-pyrazole-3-carboxylic acid

HRID 598735Notes

Reaction equation

C([O:3][C:4]([C:6]1[N:7]([C:15]2[CH:20]=[CH:19][C:18]([CH3:21])=[CH:17][CH:16]=2)[N:8]=[C:9]([C:11]([CH3:14])([CH3:13])[CH3:12])[CH:10]=1)=[O:5])C.[Li+].[OH-]>C1COCC1>[C:11]([C:9]1[CH:10]=[C:6]([C:4]([OH:5])=[O:3])[N:7]([C:15]2[CH:20]=[CH:19][C:18]([CH3:21])=[CH:17][CH:16]=2)[N:8]=1)([CH3:14])([CH3:12])[CH3:13]

Participants

Conditions

Temperature: 50 °C

Procedure

To 5-tert-butyl-2-p-tolyl-2H-pyrazole-3-carboxylic acid ethyl ester (0.5 g, 1.75 mmol) in a 40 mL scintillation vial was added 2 mL THF and 2 mL 1N LiOH. The reaction was heated at 50° C. for 1 hr after which the reaction mixture was concentrated under vacuum and the crude residue was diluted with 5 mL 1N HCl. The reaction slurry was then extracted with DCM (3×25 mL) and the combined organic layers were washed with brine (10 mL) and dried over MgSO4. The resulting solution was concentrated under vacuum to yield the desired product (0.432 g, 96%) in >95% purity. The isolated material was used without further purification.

Workup

concentrationwas concentrated under vacuum
additionthe crude residue was diluted with 5 mL 1N HCl
extractionThe reaction slurry was then extracted with DCM (3×25 mL)
washthe combined organic layers were washed with brine (10 mL)
dry with materialdried over MgSO4
concentrationThe resulting solution was concentrated under vacuum

Sources & evidence

ORD record: ord-38db1730f6e64a8791afc59e5f41343e
Source dataset: uspto-grants-2011_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07897599B2

Reaction notes

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