Trifluoroacetic acid → HCID 58181270, compound

Participants

Reaction Steps

To a solution of tert-butyl 2-[(5-{2-[5-(4-acetylpiperazin-1-yl)pyridin-2-yl]ethyl}thiophen-2-yl)carbonyl]hydrazinecarboxylate (300.0 mg) in anhydrous dichloromethane (15 ml) was added trifluoroacetic acid (0.91 ml, 12.3 mmol) at 0° C. After stirring at room temperature for 1 hr, the mixture was cooled again to 0° C., and trifluoroacetic acid (0.91 ml, 12.3 mmol) was added. After stirring at room temperature for 12.5 hrs, the reaction mixture was concentrated under reduced pressure. Ethyl acetate (30 ml) was added to the residue, and the mixture was concentrated again under reduced pressure. This operation was repeated 3 times to remove trifluoroacetic acid azeotropically. The residue was purified by aminopropylated silica gel column chromatography (2-propanol:dichloromethane=1:9). The fraction containing the target product was concentrated to about 20 ml under reduced pressure, and hexane (50 ml) was added. This operation was repeated 3 times to crystallize the target product. Hexane (100 ml) was added to the mixture, and the precipitate was filtered, washed with a mixed solvent of diethyl ether-hexane (1:1), and dried under reduced pressure to give the title compound (173.2 mg, yield 75.7%) as a white solid.

Provenance & Evidence