1046817-22-4

29526-99-6

7693-46-1

1046817-22-4

1-Methylcyclopropanol (1300 mg, 17 mmol) and 4-nitrophenyl chloroformate (3842 mg, 19 mmol) were dissolved in 50 mL of dichloromethane under nitrogen protection and cooled to 0 °C. A solution of pyridine (1.7 mL) in 10 mL of dichloromethane was added dropwise to the above solution over 10 minutes. The reaction mixture was stirred at 0°C for 90 minutes. Upon completion of the reaction, the reaction was quenched with 50 mL of aqueous 0.1 M sulfuric acid. The organic phase was separated and washed sequentially with water, saturated sodium bicarbonate solution and saturated brine, then dried over anhydrous magnesium sulfate. The desiccant was removed by filtration and the filtrate was diluted with twice the volume of hexane to gradually precipitate a solid. The solid was collected by filtration and the filtrate was concentrated to dryness to give a colorless semi-solid product. The semi-solid product was recrystallized with 50 mL of hexane, filtered hot and the solid was washed with 2 x 10 mL of boiling hexane. The filtrate was concentrated to give the target compound 1-methylcyclopropoxy-4-nitrophenyl carbonate as a white solid with a melting point of 46-48 °C. The product was confirmed by 1H NMR (CDCl3): δ 0.72-0.82 (m, 2H), 1.02-1.15 (m, 2H), 1.66 (s, 3H), 7.38 (m, 2H), 8.27 (m, 2H). Elemental analysis (C11H11NO5) calculated values: C 55.70%, H 4.67%, N 5.90%; measured values: C 55.52%, H 4.52%, N 5.94%. Note: Triethylamine should not be used in this reaction because it will have a side reaction with chloroformate.