60025-06-1

General procedure for the synthesis of 1-(4,6-dichloropyrimidin-5-yl)ethanone using 1-(4,6-dichloropyrimidin-5-yl)ethanol as starting material: 1-(4,6-dichloropyrimidin-5-yl)ethanol (8.95 g, 46.4 mmol) was dissolved in 140 mL of acetone and chromium trioxide (9.27 g, 92.7 mmol) was added. The reaction mixture was stirred at room temperature for 2.5 hours. Subsequently, the reaction was quenched by the addition of 15 mL of isopropanol and stirring was continued for 15 minutes. The reaction mixture was slowly poured into 500 mL of saturated sodium bicarbonate solution at 0°C. The aqueous phase was extracted three times with dichloromethane, and the organic phases were combined and dried with anhydrous sodium sulfate. After drying, the organic phase was concentrated to give a crude product of 8.02 g. Purification of the crude product by silica gel column chromatography with 10% ethyl acetate/hexane as eluent afforded the pure 1-(4,6-dichloropyrimidin-5-yl)ethanone 7.62 g in 86% yield. HPLC analysis showed a retention time of 4.92 min (HPLC condition H).

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