Potassium Hydroxide → 5-chloro-4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic Acid

HRID 2392266Notes

Reaction equation

[Cl:1][C:2]1[S:6][C:5]([C:7]([O:9]C)=[O:8])=[CH:4][C:3]=1[C:11]1[N:15]([CH3:16])[N:14]=[CH:13][C:12]=1[CH3:17].[OH-].[K+]>C1COCC1.O>[Cl:1][C:2]1[S:6][C:5]([C:7]([OH:9])=[O:8])=[CH:4][C:3]=1[C:11]1[N:15]([CH3:16])[N:14]=[CH:13][C:12]=1[CH3:17]

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of methyl 5-chloro-4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (7.6 g, 28.1 mmol) in THF/H2O (30 mL/5 mL) was added KOH (4.72 g, 84 mmol). The reaction mixture was heated to 50° C. for 1 h. After the mixture was concentrated and diluted with H2O, the pH was adjusted to 3. The mixture was extracted with DCM (50 mL×3). The collected organic layers were concentrated under vacuum to give the crude acid (6.8 g, 94%), which was used directly in the next step without further purification: LCMS (ES) m/z 257 (M+H)+.

Workup

concentrationAfter the mixture was concentrated
additiondiluted with H2O
extractionThe mixture was extracted with DCM (50 mL×3)
concentrationThe collected organic layers were concentrated under vacuum

Sources & evidence

ORD record: ord-61c04e26f52644b098ea1e0d8943bc2e
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08273782B2

Reaction notes

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