反应详情

2-[(4-{2-[(4′Fluorobiphenyl-4-yl)amino]ethyl}-1,3-thiazol-2-yl)thio]-2-methylpropionic acid tert-butyl ester (300 mg) obtained in Example 256-3 was dissolved in dichloromethane (4 mL), trifluoroacetic acid (4 mL) was added, and the mixture was stirred at room temperature for 20 hr. The reaction mixture was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (elution solvent; hexane:ethyl acetate=2:1 to 1:1). The obtained compound was dissolved in diethyl ether (4 mL), 4 mol/L hydrochloric acid-ethyl acetate (0.5 mL) was added, and the mixture was stirred at room temperature for 1 hr. The precipitated solid was collected by filtration to give the title compound (199 mg) as a white solid.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. customthe residue was purified by silica gel chromatography (elution solvent; hexane:ethyl acetate=2:1 to 1:1)
3. dissolutionThe obtained compound was dissolved in diethyl ether (4 mL)
4. addition4 mol/L hydrochloric acid-ethyl acetate (0.5 mL) was added
5. stirringthe mixture was stirred at room temperature for 1 hr
6. filtrationThe precipitated solid was collected by filtration