Preparation of m-dinitrobenzene
In a reaction vessel equipped with stirrer and thermometer, 70 grams of anhydrous nitric acid (density 1.52), or the equivalent quantity of at least 85% acid, is added with good external cooling to 500 grams of 100% sulfuric acid. To the well stirred acid mixture (which can be replaced by the corresponding quantity of a 30% mixed acid) is added, during the course of 30 minutes, 123 grams of dry, pure nitrobenzene. The reaction vessel is cooled with ice and care is taken that the temperature does not exceed 15-20°C. After all of the nitrobenzene has been added, stirring is continued for 1 hour at room temperature, and then the mixture is warmed to about 35° to redissolve the dinitrobenzene which has separated, and is poured with thorough stirring onto 1 kilogram of ice. The precipitated dinitrobenzene is filtered off and washed with cold water. This crude product is melted with two 400-ml portions of water, the first being made distinctly alkaline to litmus by the addition of sodium carbnate. The dinitrobenzene obtained in this way contains appreciable amounts of the 1,2 and 1,4 isomers which can be removed easily, since both of these isomers, in aqueous emulsion, react with sodium sulfite and are transformed into the easily soluble nitrobenzenesulfonic acids, whereas the 1,3 isomer is not attacked appreciably under these conditions. To effect this purification, the crude product is melted in 500 ml water at about 80°C, and 5 grams of a wetting agent is added (soap, Turkey red oil, etc.). To the well stirred oily suspension is added, over a period of 30 minutes, 20 grams of crystalline sodium sulfite, and stirring is continued for 2 hours more at 90 to 95°. The mixture becomes dark brown in color as the undesired isomers go into solution. The mixture is allowed to cool to room temperature while stirring is continued, and then the solid precipitate is separated from the mother liquor by filtration. The precipitate is remelted under 500 ml water and again cooled while stirring. The m-dinitrobenzene, obtained as almost white, small crystals, is dried below 90°. The yield of pure m-dinitrobenzene melting at 90.7°-91.4° (freezing point 90.5-91°) is 140 to 150 grams, or 83 to 90% of the theoretical amount.
The fundamental processes of dye chemistry, by H. E. Fierz-David, 111-113, 1949
1,3-Dinitrobenzene, M-DINITROBENZENE, 99-65-0, 2,4-Dinitrobenzene, Benzene, 1,3-dinitro-, meta-Dinitrobenzene, 1,3-Dinitrobenzol, Benzene, m-dinitro-, Dinitrobenzene, Dwunitrobenzen, m-DNB, Dinitrobenzene, m-, DINITROPHENYLENE, 1,3-Dinitro-benzene, Dwunitrobenzen [Polish], NSC 7189, UNII-DK8B627BU0, CCRIS 1802, CHEBI:51397, HSDB 4017, WDCYWAQPCXBPJA-UHFFFAOYSA-N, EINECS 202-776-8, NCGC00091351-02, NCGC00091351-03, AI3-02913, DSSTox_CID_4065, DSSTox_RID_77277, DSSTox_GSID_24065, 3-dinitrobenzene, CAS-99-65-0, Binitrobenzene, 1,3 Dinitrobenzene, ZINC01683353, ACMC-209sdm, AC1L1OSJ, AC1Q1GYS, WLN: WNR CNW, SCHEMBL36632, ghl.PD_Mitscher_leg0.916, KSC487A5R, UN 1597 (Salt/Mix), D194255_ALDRICH, Ex077, 442244_SUPELCO, 45966_RIEDEL, CHEMBL114070, DK8B627BU0, SCHEMBL13815840, 41980_FLUKA, 45966_FLUKA, CTK3I7058, 99-65-0 1,3-dinitrobenzene, NSC7189, m-Dinitrobenzene, liquid or solid, MolPort-001-783-834, LTBB002347, WT299, NSC-7189, Tox21_111119, Tox21_400032, ANW-41048, AR-1D3775, STL282471, AKOS000120046, DB02680, LS-2198, MCULE-7187890602, RP23060, RTR-033639, NCGC00091351-01, NCGC00091351-04, AJ-29747, AK-48643, AN-24518, CJ-27728, KB-10434, AB1003212, DB-032004, ST2414828, TR-033639, D0817, D1317, FT-0084941, FT-0615610, FT-0632546, X7172, A23174, Q-9475, AE-562/40238126, 3B4-1298, I01-7042, I14-91985, m-Dinitrobenzene, liquid or solid [UN1597] [Poison], m-Dinitrobenzene, liquid or solid [UN1597] [Poison], UNII-1PRF48770M component WDCYWAQPCXBPJA-UHFFFAOYSA-N, InChI=1/C6H4N2O4/c9-7(10)5-2-1-3-6(4-5)8(11)12/h1-4