Potassium Hydroxide → 4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid

HRID 2392021Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[N:4][N:5]([CH2:16][CH3:17])[C:6]=1[C:7]1[CH:8]=[C:9]([C:12]([O:14]C)=[O:13])[S:10][CH:11]=1.[OH-].[K+]>C1COCC1.O>[Cl:1][C:2]1[CH:3]=[N:4][N:5]([CH2:16][CH3:17])[C:6]=1[C:7]1[CH:8]=[C:9]([C:12]([OH:14])=[O:13])[S:10][CH:11]=1

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of methyl 4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (0.3 g, 1.1 mmol) in THF/H2O (5 mL/0.5 mL) was added KOH (0.2 g, 3.4 mmol). The reaction mixture was heated to 50° C. for 4 h and then concentrated and diluted with H2O (2 mL). The pH was adjusted to 3 with aqueous HCl. The mixture was extracted with DCM (3×5 mL) and the collected organic fractions were concentrated under vacuum to give crude 4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid (260 mg) which was used directly without further purification. LC-MS (ES) m/z=256 (M+H)+.

Workup

concentrationconcentrated
additiondiluted with H2O (2 mL)
extractionThe mixture was extracted with DCM (3×5 mL)
concentrationthe collected organic fractions were concentrated under vacuum

Sources & evidence

ORD record: ord-31bb2bc7c9d046aab4fa683c44d62b32
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08273782B2

Reaction notes

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