131467-06-6

933702-55-7

General procedure for the synthesis of 2-chloropyrimidine-5-carbaldehyde from 2-chloro-5-vinylpyrimidine: 2-chloro-5-vinylpyrimidine (0.1 g, 0.7 mmol) was dissolved in a mixed solvent of dioxane (1 mL) and water (1 mL) at room temperature, and 2,6-dimethylpyridine (0.188 g, 1.76 mmol), osmium tetroxide (3.5 mg 0.007 mmol) and sodium periodate (0.59 g, 2.81 mmol). The reaction mixture was stirred at room temperature for 2-3 hours. After completion of the reaction, the reaction was quenched with ethyl acetate and water. The organic layer was separated and washed sequentially with water and brine. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford 2-chloropyrimidine-5-carbaldehyde (0.04 g, 40% yield) using 20% ethyl acetate-hexane as eluent. The product was characterized by 1HNMR (CDCl3, 300 MHz): δ 10.15 (s, 1H), 9.07 (s, 2H).