Preparation of 4-chloro-3-nitrobenzenesulfonic acid
The reaction is carried out in a round-bottomed flask fitted with an efficient stirrer, thermometer, and dropping funnel, and surrounded by a larger container through which cold or hot water can be circulated. 112.5 grams (1 mole) of chlorobenzene is added to a mixture of 220 grams of 100 % sulfuric acid and 125 grams of oleum (20% sulfur trioxide) with stirring, over the course of about 30 minutes. The temperature rises to 70 or 80°C. When it begins to drop after the addition of the chlorobenzene has been completed, the surrounding water bath is heated to boiling and stirring is continued for about 2 hours, or until a test portion of the reaction mixture on dilution with water shows no oil droplets and has no odor of chlorobenzene when heated. (A completely clear solution is usually not obtained, because a very small amount of dichlorodiphenylsulfone is formed in the reaction. This does not separate as an oil on dilution, however, but as crystalline flocks.) The reaction mixture is cooled in ice and 65 grams of fuming nitric acid (sp.gr. 1.52) is added drop wise with stirring. The addition requires about 1.5 to 2 hours, and should be regulated so that the temperature of the reaction mixture remains between 15 and 20°. The cooling bath is removed and stirring is continued for 3 to 4 hours at room temperature. The 4-chloro-3-nitrobenzenesulfonic acid partially crystallizes, transforming the whole mixture to a stiff paste which must be broken up with a glass rod or a spatula to permit further stirring. When a nitrometer test shows that the residual nitric acid corresponds to the small excess used (about 2 grams), the reaction mixture is stirred with a cooled mixture of 1 liter of saturated salt solution and 500 ml water. The precipitate is filtered off yielding about 370 grams of moist cake, consisting of about 72% of solid material. The sodium 2-nitrochlorobenzene-4-sulfonate can be obtained in a pure state by recrystallizing from hot water, dilute salt solution, or aqueous alcohol.
The fundamental processes of dye chemistry, by H. E. Fierz-David, 104-105, 1949
4-Chloro-3-nitrobenzenesulfonic acid, 121-18-6, Benzenesulfonic acid, 4-chloro-3-nitro-, o-Nitrochlorobenzene-p-sulfonic acid, 2-Nitrochlorobenzene-4-sulfonic acid, AC1Q5ANP, AC1L26WZ, 4-sulfo-2-nitrochlorobenzene, SCHEMBL332971, 3-Nitro-4-chlorobenzenesulfonate, CTK4B2231, NSC7827, MolPort-002-321-290, RPKWNMFDAOACCX-UHFFFAOYSA-N, NSC 7827, NSC-7827, ZINC1688383, EINECS 204-452-1, 3-Nitro-4-chlorobenzenesulfonic acid, 3759AA, AR-1G1658, BBL001178, STK368551, 4-Chloro-3-nitrobenzenesulphonic acid, 4-chloro-3-nitro-benzenesulfonic acid, 4-chloro-3-nitrobenzene sulfonic acid, AKOS005444329, MCULE-6372248739, VZ34783, 4-Chloro-3-nitro benzene sulfonic acid, Benzenesulfonic acid,4-chloro-3-nitro-, 4-chloranyl-3-nitro-benzenesulfonic acid, 4-chloro-3-nitrobenzene-1-sulfonic acid, 2-Nitro-1-Chlorobenzene-4-Sulfonic Acid, 4-chloro-3-nitrobenzene-1-sulphonic acid, AC-11589, AJ-29939, AK115329, AN-43378, OR032219, SC-16338, DB-061884, KB-190762, FT-0613190, ST50561898, T7346, A804684, W-108460, 3B3-065423
C6H4ClNO5S, CID67132, Potassium 4-chloro-3-nitrobenzenesulfonate, T1699, 68140-75-0