2,5-Dimethyl-1,3-dinitrobenzene → 2,5-Dimethyl-3-nitroaniline

Temperature

110 °C

To a stirred solution of p-xylene (10.4 g, 97.9 mmol) in concentrated sulfuric acid (20 mL), cooled in an ice bath, was added 90% nitric acid (12.4 mL, 264 mmol) dropwise over 50 min. The resulting mixture was heated to 80° C. for 2 h, then poured onto ice and extracted with CH2Cl2 (2×400 mL). The combined organic extracts were washed with saturated aqueous NaHCO3, then brine, then dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was partially purified by silica gel chromatography, eluting with a gradient of hexane:EtOAc—90:10 to 60:40. The resulting solid was recrystallized from CH2Cl2 to yield 2,5-dimethyl-1,3-dinitrobenzene as a white solid. 2,5-Dimethyl-1,3-dinitrobenzene (3.68 g, 18.8 mmol) was dissolved in AcOH (35 mL) and iron powder (1.95 g, 34.9 mmol) was added. The mixture was heated to 110° C. for 3 h, then filtered through a pad of Celite, washing with EtOAc and H2O. The filtrate was concentrated in vacuo to remove most of the solvent and the residue was partitioned between saturated aqueous NaHCO3 (200 mL) and EtOAc (200 mL). The organic layer was washed with brine, then dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with a gradient of hexane:EtOAc—100:0 to 60:40, to give the title compound. MS: m/z=167 (M+1).

1. filtrationfiltered through a pad of Celite
2. washwashing with EtOAc and H2O
3. concentrationThe filtrate was concentrated in vacuo
4. customto remove most of the solvent
5. customthe residue was partitioned between saturated aqueous NaHCO3 (200 mL) and EtOAc (200 mL)
6. washThe organic layer was washed with brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe crude product was purified by silica gel chromatography
11. washeluting with a gradient of hexane

ORD record

ord-9fe7e9a03c69454ebcb4efa9b45c955a

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07947677B2