Nitroaniline from m-dinitrobenzene

Dissolve 6.7g (0.04 mol) of m-dinitrobenzene in 50 ml of hot methanol in a 250-ml round-bottomed flask and add, with shaking, the previously prepared methanolic solution of sodium hydrogen sulphide. Attach a reflux condenser and boil the mixture for 20 minutes ignore any further sodium carbonate which may precipitate. Allow the reaction mixture to cool and fit the condenser for distillation. Distil off most of the methanol (100-120 ml) from a water bath. Pour the liquid residue with stirring into about 200 ml of cold water. Collect the yellow crystals of m-nitroaniline by suction, wash with water and recrystallise from 75 per cent aqueous methanol. The yield of bright yellow crystals, m.p. 114 °C, is 3.7 g (69%). 

Pd-C in both ethanol and DMF, little, if any, selectivity was obtained product ratios were 50 50 in ethanol and 60 40 in DMF. Palladium black in ethanol, which afforded 4-amino-5-nitroveratrole in 70-75% yield from 4,5-dinitroveratrole, provided no selectivity with 2,4-dinitroaniline, as well as with o- and m-dinitrobenzenes both nitro groups were hydrogenated.140 Reduction by sodium borohydride and Pd-C in methanol also does not appear to be selective, as 1,2,4-triaminobenzene is formed.141 It is of interest that over Pt-C in acidic alcohol 2,4-dinitroaniline is selectively hydrogenated at the 4-nitro group to give 4-amino-2-nitroaniline in 70% yield.142... 

Diamino-4,6-dinitrobenzofuroxan (DADNBF) (82), an impact insensitive high performance explosive (VOD 8050 m/s, d = 1.91 g/cm ), has been prepared in four steps from l,3,5-trichloro-2,4-dinitrobenzene (78), ° and also by treating the Meisenheimer complex (83) with excess hydroxylamine hydrochloride in aqueous base. DADNBF has also been synthesized in five steps starting from 2-nitroaniline. ... 

Cognate preparation, p-Dinitrobenzene. Use 34 g (0.25 mol) of p-nitroaniline (Expt 6.68) and proceed exactly as above to the point where all the suspension of p-nitrobenzenediazonium fluoroborate has been added. Filter the reaction mixture with suction, wash the residue well with water, twice with 25 ml of 5 per cent sodium hydroxide solution and finally with water. Dry the solid at 100-110°C, powder it and extract it with four 150ml portions of boiling toluene. Remove the toluene with a rotary evaporator and recrystallise the residue from about 120 ml of boiling glacial acetic acid. The yield of p-dinitrobenzene (reddish-yellow crystals), m.p. 173 °C, is 30g (71.5%). Further recrystallisation from ethanol affords pale yellow crystals of the same m.p. The p.m.r. spectrum is noted above. 

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