A. 1,5-Dichloro-2,4-dinitrobenzene Caution! (Note 1). To a well-stirred solution of 140 g. (1.386 moles) of potassium nitrate in 500 ml. of concentrated sulfuric acid is added 100.0 g. (0.680 mole) of m-dichlorobenzene in one portion. The temperature of the reaction mixture rises during a few minutes to 135–140°, then drops slowly to 125°. The stirred mixture is kept at 120–135° for an additional hour. After the reaction mixture has been cooled to about 90° it is poured over 1.5 kg. of crushed ice. The precipitated product is collected by suction filtration, drained well on the funnel, and dissolved in about 1 l. of boiling 95% ethanol. A small amount of insoluble impurity is removed by filtration of the hot solution by gravity through a fluted filter paper, and the product is allowed to crystallize in the refrigerator at about 0° (Note 2). The yield of yellow needles is 112–115 g. (70–71.5%), m.p. 103–104°.

B. 1,5-Diamino-2,4-dinitrobenzene Ammonia gas from a tank is bubbled into a well-stirred, clear yellow solution of 60.0 g. (0.253 mole) of 1,5-dichloro-2,4-dinitrobenzene in 400 ml. of technical grade ethylene glycol (heated to 140°), at such a rate that the gas is just absorbed. Within 30 minutes the color of the solution changes through orange to deep red. About 1 hour after the start of the reaction an orange, crystalline precipitate begins to separate. Heating is continued for an additional 2 hours as a slow stream of ammonia gas is bubbled through the reaction mixture. Finally, the reaction mixture is cooled to room temperature, the product is collected by suction filtration, and the finely divided orange-brown crystals are washed with boiling water and boiling ethanol. The yield of dried product, m.p. 300° (subl.), is 44–48 g. (88–95.5%) (Note 3).

C. 2,4,5-Triaminonitrobenzene. A well-stirred slurry (Note 4) of 22.5 g. (0.114 mole) of 1,5-diamino-2,4-dinitrobenzene in 150 ml. of water is heated (Note 4) to the boiling point under reflux in a 500-ml. three-necked flask. To this vigorously stirred mixture, a clear orange-red solution of sodium polysulfide (prepared by heating a mixture of 30.0 g. of sodium sulfide nonahydrate, 7.25 g. of sulfur, and 125 g. of water) is added dropwise during a period of 1.5 hours. After completion of the addition, reflux of the well-stirred reaction mixture is maintained for an additional 1.5 hours. The resultant deep red mixture is cooled to 0° and the total insoluble material is collected by suction filtration. This residue of product, sulfur, and some starting material is thoroughly extracted with five 200-ml. portions of boiling water. The combined hot extracts are filtered by gravity and cooled to room temperature to yield 9.5–10.0 g. (49.5–52%) of red needles, m.p. 200–207°, of 2,4,5-triaminonitrobenzene.