Lithium Hydroxide → HCID 657065, compound

Participants

Reaction Steps

3-[(2,4-Dichloro-benzoyl)-isopropyl-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester (3) (345 mg, 0.77 mmol) was dissolved in a mixture of THF-MeOH—H2O (3:2:1) (30 mL) and then 4.6 ml of LiOH 1N was added to it. After 120 min of stirring at room temperature; solvant was removed and then partitioned between 25 ml of H2O, 4 ml of KHSO4 5% and 25 ml of EtOAc. The organic, layer was separated and the aqueous phase was washed twice with ethyl acetate (2×10 mL). The combined ethyl acetate layer was dried (MgSO4), concentrated and the residue was purified by preparative chromatography (10% MeOH/CH2Cl2) to obtain 175 mg (53%) as a white solid of 3-[(2,4-Dichloro-benzoyl)-isopropyl-amino]-5-phenyl-thiophene-2-carboxylic acid. NMR 1H (DMSO, 400 MHz): Rotamer 95/05: 7.82 ppm (m, Haro, minor rotamer); 7.69 ppm (d, 2H, Haro); 7.61 ppm (d, 1H, Haro); 7.51-7.37 ppm (m, 4H, Haro); 7.35-7.28 ppm (m, 2H, Haro), 4.89 ppm (hex, 1H, N—CH(CH3), major rotamer); 3.84 ppm (hex, N—CH(CH3), minor rotamer); 1.36 ppm (d, 3H, N—CH(CH3), major rotamer); 1.25 ppm (d, N—CH(CH3), minor rotamer); 1.03 ppm (d, 3H, N—CH(CH3), major rotamer); 0.93 ppm (d, N—CH(CH3), minor rotamere).

Provenance & Evidence