Citric Acid → 5-Chloro-3-(trifluoromethyl)-1-benzothiophene-2-carboxylic acid
Reaction equation
[Cl:1][C:2]1[CH:18]=[CH:17][C:5]2[S:6][C:7]([C:13]([O:15]C)=[O:14])=[C:8]([C:9]([F:12])([F:11])[F:10])[C:4]=2[CH:3]=1.[Li+].[OH-].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1.CO.O>[Cl:1][C:2]1[CH:18]=[CH:17][C:5]2[S:6][C:7]([C:13]([OH:15])=[O:14])=[C:8]([C:9]([F:12])([F:11])[F:10])[C:4]=2[CH:3]=1Participants
5
Procedure
A mixture of compound 18e (574 mg, 1.95 mmol) and LiOH (187 mg, 7.80 mmol) in THF/MeOH/H2O (4/4/4 mL) was stirred for 4 h. A 15% citric acid solution (20 mL) was added, and the mixture was then extracted with EtOAc (3×). The combined extracts were washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue, compound 18f, was dried under reduced pressure for 18 h and was used without purification.