Nitric Acid → 4-Ethyl-2-nitroaniline

Temperature

0 °C

4-Ethylaniline (15.0 g, 124 mmol) was carefully added to acetic anhydride (100 mL, 1.06 mol) that was pre-cooled to 0° C., and the mixture was warmed to rt over 30 min, then recooled to 0° C., and nitric acid (7.90 mL of a 70% v/v aq. solution, 124 mL) was added dropwise. After 30 min, the reaction mixture was quenched into an ice-water bath, the resulting slurry was filtered, and the filter cake was dried in vacuo. The crude solid product was dissolved in 6M HCl (100 mL) and dioxane (60 mL), and the resulting mixture was heated at 0° C. After 3 h, the reaction mixture was cooled to rt and concentrated in vacuo. The crude residue was suspended in EtOAc and neutralized via addition of 6N NaOH. The layers were separated, and the aq. layer was extracted with EtOAc. The combined organics were washed with brine, dried (Na2SO4), filtered and concentrated in vacuo to afford the title compound, i-6a, m/z (ES) 167 (MH)+.

1. temperaturethe mixture was warmed to rt over 30 min
2. customrecooled to 0° C.
3. customthe reaction mixture was quenched into an ice-water bath
4. filtrationthe resulting slurry was filtered
5. customthe filter cake was dried in vacuo
6. dissolutionThe crude solid product was dissolved in 6M HCl (100 mL)
7. temperaturedioxane (60 mL), and the resulting mixture was heated at 0° C
8. waitAfter 3 h
9. temperaturethe reaction mixture was cooled to rt
10. concentrationconcentrated in vacuo
11. additionThe crude residue was suspended in EtOAc and neutralized via addition of 6N NaOH
12. customThe layers were separated
13. extractionthe aq. layer was extracted with EtOAc
14. washThe combined organics were washed with brine
15. dry with materialdried (Na2SO4)
16. filtrationfiltered
17. concentrationconcentrated in vacuo

ORD record

ord-209dac42c36442e4b3bcd85ca536004e

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09029377B2