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

Temperature

0 °C

3,4-dibromotoluene (108.11 mL, 800 mmol) was added dropwise over 4 hours to nitric acid (90%, 280 mL, 6000 mmol) that was cooled to 0° C. under a nitrogen atmosphere with 10 mechanical stirring. The internal temperature of the mixture was maintained below 10° C. during the addition and was stirred for 1 hour at 0° C. after completion of addition. Water (840 mL) was added drop-wise to the mixture maintaining the internal temperature below 10° C. The crude product was collected by filtration and was 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 produce 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. temperaturemaintaining the internal temperature below 10° C
4. filtrationThe crude product was collected by filtration
5. washwas washed 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-cbd78066244c49f494eb986e8ec868ac

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07521447B2