1-Chloro-2,4-Dinitrobenzene → N-Methoxy-2,4-dinitroaniline

2,4-Dinitrochlorobenzene (4.05 g (20.0 mmol)) and methoxylamine hydrochloride (2.00 g (23.9 mmol)) were dissolved in 15 ml of acetonitrile. To this mixture, under ice cooling and with stirring, triethylamine (7.00 ml (50.2 mmol)) was added. After being stirred for 24 hours at room temperature, the resulting black solution was concentrated under reduced pressure.Water and dilute hydrochloric acid were added to the residue and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was then subjected to silica gel column chromatography with ethyl acetate-hexane (1:5) as eluent, to give 2.26 g (53%) of N-(2,4-dinitrophenyl)-O-methylhydroxylamine as yellow crystals.