4-Methyl-2-nitroaniline → 2-Bromo-4-methyl-6-nitroaniline

A solution of bromine (23.24 mL, 453.5 mmol) in glacial acetic acid (50 mL) was added dropwise over 2 h to a mechanically-stirred suspension of 4-methyl-2-nitroaniline (60.00 g, 394.3 mmol) in glacial acetic acid (200 mL) at room temperature under a nitrogen atmosphere. The mixture was stirred at room temperature 1 h, and then most of the acetic acid was removed under reduced pressure. The resultant orange solid was dissolved in a mixture of saturated aqueous sodium bicarbonate (1500 mL) and ethyl acetate (500 mL). The layers were separated and the aqueous solution was again extracted with ethyl acetate. The combined organic layers were washed once with water, dried (MgSO4), filtered, and concentrated under reduced pressure to afford the title compound of Step A as an orange solid melting at 64°-65.5° C. (89.694 g, 98%). 1H NMR (CDCl3): δ2.28 (s,3H), 6.45 (br s,2H), 7.55 (s, 1H), 7.94 (s, 1H).

1. custommost of the acetic acid was removed under reduced pressure
2. dissolutionThe resultant orange solid was dissolved in a mixture of saturated aqueous sodium bicarbonate (1500 mL) and ethyl acetate (500 mL)
3. customThe layers were separated
4. extractionthe aqueous solution was again extracted with ethyl acetate
5. washThe combined organic layers were washed once with water
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure

ORD record

ord-bce3bb869e764396bc23e7298aa8e4ba

Source dataset

uspto-grants-1997_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05633218