反应详情

温度

8 °C

To a 5 L three necked round bottom flask equipped with a mechanical stirrer was added 4-nitro-2-methoxytoluene (150.0 g, 0.8973 mol), HOAc (900 mL) and Ac2O (900 mL). The mixture was stirred and cooled to 8° C. with an acetone/ice bath. Concentrated H2SO4 (136 mL) was carefully added while keeping the pot temperature <190 C. After cooling to 0° C., CrO3 (252.6 g, 2.526 mol, 2.815 equiv.) was added portion-wise over 1 hour while maintaining the reaction temperature between 0-10° C. After the addition, the mixture was stirred at 0° C. for 30 minutes at which time the reaction was complete. The reaction mixture was then carefully poured into ice (1.5 kg) with stirring to give a slurry. The remaining black gummy residue was rinsed with HOAc (3×100 mL), and the washes were added to the slurry. After stirring for 10 minutes, the slurry was filtered. The cake was washed with water (3×400 mL) and suction dried for 17 hours to give 4-nitro-2-methoxy-(a,a-bisacetoxy)toluene (1A, 129.0 g, 51%). 1H NMR (CDCl3) d 8.02 (s, 1H), 7.89 (d, J=8.4 Hz, 1H), 7.77 (s, 1H), (d, 8.4 Hz, 1H), 3.98 (s, 3H), 2.16 (s, 6H).

1. temperatureAfter cooling to 0° C.
2. temperaturewhile maintaining the reaction temperature between 0-10° C
3. additionAfter the addition
4. stirringthe mixture was stirred at 0° C. for 30 minutes at which time the reaction
5. stirringwith stirring
6. customto give a slurry
7. washThe remaining black gummy residue was rinsed with HOAc (3×100 mL)
8. additionthe washes were added to the slurry
9. stirringAfter stirring for 10 minutes
10. filtrationthe slurry was filtered
11. washThe cake was washed with water (3×400 mL) and suction
12. customdried for 17 hours