Water → 5-Methylpyrazine-2-carboxaldehyde

Participants

Reaction Steps

In methanol (15 ml), 5-methylpyrazine-2-carboxylic acid (manufactured by Tokyo Kasei Kogyo Co., Ltd.) (1.25 g) was dissolved. Then, the solution was added with WSCI hydrochloride (2.59 g) and N,N-dimethylaminopyridine (1.65 g) in this order, followed by stirring at room temperature for 3 hours. The reaction solution was added with water and then extracted with chloroform. The organic layer was washed with saturated saline solution and then dried with anhydrous sodium sulfate. The solvent was distilled off and the resulting crude product was then purified through silica gel column chromatography (chloroform/methanol). The purified product was dissolved in ethanol (15 ml) and THF (8 ml) and added with calcium chloride (1.11 g). After that, the reaction solution was cooled to 0° C. and then gradually added with sodium borohydride (757 mg), followed by stirring at room temperature for 19 hours. The reaction solution was added with a 1 mol/l citric acid solution (40 ml), followed by extraction with ethyl acetate. The organic layer was washed with saturated saline solution and then dried with anhydrous sodium sulfate, followed by distilling the solvent off. The residue was dissolved in chloroform (10 ml) and then added with manganese dioxide (chemically processed product) (2.2 g), followed by stirring at room temperature for 1 hour. After completion of the reaction, the catalyst was filtrated out through Celite and the solvent was then distilled off. The crude product obtained was purified through silica gel column chromatography (chloroform/methanol), thereby obtaining the subject compound (35.9 mg) as a colorless oily substance.

Provenance & Evidence