Nitric Acid → 1,2-Dibromo-4-methyl-5-nitrobenzene

Temperature

0 °C

3,4-dibromotoluene (108.11 mL, 800 mmol) was added dropwise with mechanical stirring over 4 hours to nitric acid (90%, 280 mL, 6000 mmol) that was cooled to 0° C. under a nitrogen atmosphere. The internal temperature of the mixture was maintained below 10° C. during the addition and the reaction mixture was stirred for 1 hour at 0° C. after completion of addition. Water (840 mL) was added drop-wise to the mixture while maintaining the internal temperature below 10° C. The crude product was collected by filtration and washed with water (5×500 mL) to remove the excess nitric acid. The solids were dried under high vacuum and purified by recrystallization from ethanol (800 mL) to provide 180.9 g (77% yield) of the desired product as a solid. 1H NMR (400 MHz, CDCl3) δ 8.24 (s, 1H), 7.64 (s, 1H), 2.55 (s, 3H).

1. temperatureThe internal temperature of the mixture was maintained below 10° C. during the addition
2. additionafter completion of addition
3. temperaturewhile maintaining the internal temperature below 10° C
4. filtrationThe crude product was collected by filtration
5. washwashed with water (5×500 mL)
6. customto remove the excess nitric acid
7. customThe solids were dried under high vacuum
8. custompurified by recrystallization from ethanol (800 mL)

ORD record

ord-1d3bf341a6db486095237e3ba9ff32bc

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08026233B2