Lithium hydroxide, monohydrate → 4-bromo-1-[2-(4-chlorophenyl)-2-oxoethyl]-1H-pyrrole-2-carboxylic acid

HRID 1753135Notes

Reaction equation

O[Li].O.[Br:4][C:5]1[CH:6]=[C:7]([C:20]([O:22]C)=[O:21])[N:8]([CH2:10][C:11]([C:13]2[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=2)=[O:12])[CH:9]=1>C1COCC1>[Br:4][C:5]1[CH:6]=[C:7]([C:20]([OH:22])=[O:21])[N:8]([CH2:10][C:11]([C:13]2[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=2)=[O:12])[CH:9]=1

Participants

Conditions

Temperature: 40 °C

Procedure

LiOH H2O (0.2 M, 6.8 mL, 1.36 mmol) was added portionwise to a solution of crude methyl 4-bromo-1-[2-(4-chlorophenyl)-2-oxoethyl]-1H-pyrrole-2-carboxylate (210 mg, 0.39 mmol) in THF (0.5 mL), and the mixture stirred at 40° C. for 3 h, after which time the TLC analysis showed consumption of starting material ester. The reaction mixture was diluted with aqueous NaOH solution (1 M) (50 mL) and the mixture washed with CH2Cl2 (100 mL). The aqueous layer was acidified to pH 2 with aqueous HCl solution (1 M) and was extracted with CH2Cl2 containing 30% of propan-2-ol (2×150 mL). The organic layers were combined, dried (MgSO4) and concentrated in vacuo to give 4-bromo-1-[2-(4-chlorophenyl)-2-oxoethyl]-1H-pyrrole-2-carboxylic acid (100 mg, yield 75%). This crude material was used in the next step without further purification.

Workup

customconsumption of starting material ester
additionThe reaction mixture was diluted with aqueous NaOH solution (1 M) (50 mL)
washthe mixture washed with CH2Cl2 (100 mL)
extractionwas extracted with CH2Cl2 containing 30% of propan-2-ol (2×150 mL)
dry with materialdried (MgSO4)
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-c41a8e22d66649df92bf64329abe4de2
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09163029B2

Reaction notes

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