Trifluoroacetic acid → HCID 57940616, compound

Participants

Reaction Steps

At room temperature, trifluoroacetic acid (1.4 mL) was added to a solution of the above-obtained 4-[5-(4-ethoxy-2-pyridyl)-1-(6-methoxy-3-pyridyl)pyrazole-3-carbonyl]piperazine-1-carboxylic acid tert-butyl ester (0.135 g) in methylene chloride (2.7 mL), and the mixture was stirred for 30 minutes. The solvent was removed under reduced pressure, and the residue was dissolved in ethanol (2.7 mL). To the mixture were added 35% aqueous formalin solution (0.114 g), acetic acid (0.076 mL) and sodium cyanoborohydride (50.0 mg). The resultant mixture was stirred for 100 minutes at room temperature. Sodium cyanoborohydride (33.3 mg) was further added thereto, and the mixture was stirred for 50 minutes. The reaction mixture was partitioned between saturated aqueous sodium hydrogencarbonate and chloroform. The organic layer was dried over sodium sulfate anhydrate. After filtration, the solvent was removed under reduced pressure. The residue was purified through silica gel column chromatography (chloroform-methanol). Subsequently, the residue was purified through silica gel thin-layer chromatography (chloroform-methanol), to thereby give the title compound as an oily product (86.9 mg, 78%).

Provenance & Evidence