Trifluoroacetic acid → (E)-3-(8-[(E)-2-(4-Isopropyl-1,3-thiazol-2-yl)-1-ethenyl]-2-(3-[(methylamino)-carbonyl]piperidino}-4-oxo-4H-pyrido[1,2-a]pyrimidin-3-yl)-2-propenoic acid

Participants

Reaction Steps

The tert-butyl (E)-3-(8-[(E)-2-(4-isopropyl-1,3-thiazol-2-yl)-1-ethenyl]-2-{3-[(methylamino)carbonyl]piperidino}-4-oxo-4H-pyrido[1,2-a]pyrimidin-3-yl)-2-propenoate (192 mg, 0.341 mmol) obtained in (B) was added with trifluoroacetic acid (5.0 ml) and stirred at room temperature for 1.5 hours. After the reaction was completed, the trifluoroacetic acid was evaporated under reduced pressure, and the residue was neutralized with 0.1 N sodium hydroxide and phosphate buffer (pH 7-8) and extracted with chloroform. The organic layer was dried over sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by thin layer chromatography (chloroform:methanol and chloroform:methanol:water=8:3:1, v/v, lower layer) to obtain the title compound (49.0 mg, 28%).

Provenance & Evidence