Nitric Acid → 2-Bromo-1,3-difluoro-4-nitrobenzene

1-Bromo-2,6-difluorobenzene (Oakwood Products Inc., West Columbia, S.C.) (15.4 mL, 104 mmol) was treated with H2SO4 (77 mL of 95-98% pure, 1445 mmol) and cooled in an ice bath. It was treated with HNO3 (68 mL of 69-70% pure, 1050 mmol) slowly dropwise via a dropping funnel and stiffed for and additional 30 min. The mixture was poured onto ice (500 mL) and stirred vigorously for 3 min. The resulting suspension was extracted with DCM (4×100 mL), washed with brine (500 mL) and dried over Na2SO4, filtered and concentrated affording crude 2-bromo-1,3-difluoro-4-nitrobenzene (32.55 g, 137 mmol) as a bright yellow crystalline solid. 1H NMR (400 MHz, CDCl3) δ ppm 8.13 (1H, ddd, J=9.1, 8.1, 5.5 Hz), 7.13 (1H, ddd, J=9.3, 7.1, 2.0 Hz). 19F NMR (376 MHz, CDCl3) δ ppm −92.06 (1F, s), −104.31 (1F, s). m/z (ESI, +ve ion) 259.1/261.1 (M+Na)+.

1. temperaturecooled in an ice bath
2. customadditional 30 min
3. additionThe mixture was poured onto ice (500 mL)
4. extractionThe resulting suspension was extracted with DCM (4×100 mL)
5. washwashed with brine (500 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-7c1e56d3e91e494d8694ac6dd40de171

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394297B2