Trifluoroacetic acid → 5-(4-Acetylpiperazin-1-yl)pyridine-2-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-(6-formylpyridin-3-yl)piperazine-1-carboxylate (270.4 mg, 0.9281 mmol) in dichloromethane (2.5 ml) was added trifluoroacetic acid (2.5 ml) at 0° C. After stirring at 0° C. for 1 hr, the reaction mixture was concentrated under reduced pressure. Anhydrous dichloromethane (2.5 ml) was added to the residue, acetic anhydride (0.105 ml, 1.114 mmol) was added, and the mixture was stirred at room temperature for 1 hr. Saturated aqueous sodium hydrogen carbonate solution was added, and the mixture was extracted 5 times with ethyl acetate. The combined organic layer was dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methanol:dichloromethane=1:30) to give 5-(4-acetylpiperazin-1-yl)pyridine-2-carbaldehyde (147.0 mg, yield 67.9%) as a slightly yellow solid.

Provenance & Evidence