2,3,5-Trimethylpyridine → 3,5-Dimethylpyridine-2-carbaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In dichloromethane (15.0 ml), 2,3,5-trimethyl-pyridine (1.29 g) was dissolved. The reaction solution was cooled to 0° C. and added with meta-chloroperbenzoic acid (2.53 g), followed by stirring at room temperature for 1.5 hours. The reaction solution was added with a 1 mol/l sodium hydroxide aqueous solution and then subjected to extraction with chloroform. Subsequently, the organic layer was washed with saturated saline solution and dried with anhydrous sodium sulfate. The drying agent was filtrated out and the solvent was then distilled off, followed by dissolving the resulting residue in dichloromethane (25.0 ml). The reaction solution was added with trifluoroacetic anhydride (2.8 ml) and subjected to thermal reflux for 3.5 hours. After the reaction solution had been cooled to room temperature, the solvent was distilled off. The residue obtained was dissolved in methanol (60.0 ml). After having been cooled to 0° C., the reaction solution was added with a 12.5% sodium methoxide/methanol solution to adjust to pH 10, followed by stirring at room temperature for 16.5 hours. After the solvent had been distilled off, the residue was added with distilled water and extracted with chloroform. The organic layer was washed with saturated saline solution and dried with anhydrous sodium sulfate. The drying agent was filtrated out and the solvent was then distilled off, followed by dissolving the resulting residue in chloroform (30.0 ml). The reaction solution was added with manganese dioxide (chemically processed product) (6.10 g) and then stirred at room temperature for 18 hours. The reaction solution was filtrated through Celite. The solvent in the filtrate was distilled off and the residue obtained was then purified through silica gel column chromatography (chloroform/ethyl acetate), thereby obtaining the subject compound (1.14 g) as a yellow oily substance.

Herkunft & Nachweise