SU833956A1 - Method of preparing 2-nitro-1,1-diphenylamino-4-sulfanilide - Google Patents

Description

(54) METHOD FOR OBTAINING 2-NITRO-1, l-DIPHENYLAMIN-: -4-SULPHANE: 5IDA

L

The purpose of the invention is to increase the yield of the target product, improving the process technology.

This goal is achieved by the method of obtaining 2-nitro-1, l-diphenylamine-4-sulfanilide by reacting 4-chloro-3-nitrobenzenesulfonyl chloride with an excess of aniline in the presence of a condensing agent and a wetting agent, a product of naphthalene 2-sulfonic acid, with formaldehyde at a temperature of 20 up to 100 ° C, followed by separation of the target product, using calcium carbonate or caustic magnesite as a condensing agent.

The process proceeds as follows.

.% co, .H3d fQr-NO

SOgCl

2 T eoC

SOgMш + Kg-Clg-i-C02-t- 2H20

SOgM in the process uses caustic magnesite, which is a mixture of the following composition,%: Magnesium oxide Not less than 75-88 Calcium oxide Not more than 1.8-4, Creme dioxide The same 1.6-3.5 Amount of sesquioxides of iron and aluminum, 0-2.2 mini Sulfates (in terms of SO.) 2.0 Carbonated salts (in terms of CO,) 1.4 Loss at 6.0-18 calcinations The proposed method allows to increase the yield of the target product up to 98% against 89% while simultaneously improving the quality of the target products and the process technology by using the minimum excess of a lina, which affects and energy consumption wastes at high consumption rates of aniline and on the volume of wastewater containing aniline. Example 1. A three-ml bottle with a capacity of 100 ml equipped with a stirrer, thermometer, reflux water cooler and charging hopper is charged with 22.5 ml water, 1.94 g of caustic magnesite powder (GOST 1216-75) and stir 20 min. Then, 8.08 g of aniline (6% excess) and 0.4 g of a dispersion of a torus NF (condensation product of 2-succinic naphthalene with formaldehyde) are loaded. After 20 minutes, stir. In the suspension, while loading for 20 minutes, 10.5 g of 4-chloro-3-nitrobenzeneLufochloride, heat to 40 ° C for 15 minutes and stir at this temperature for 5 hours. Then, for 1 hour, the reaction mass is heated to and give 10 hours. At the end of the exposure to the reaction mass slowly, for 15-20 minutes. 26 ml of water is charged with a temperature of 25 ° C. In this case, the dye is cooled, cooled, and granulated. Then, replacing the reflux condenser with a straight line, the mass is heated before and the aniline is stripped with live steam for 1 hour. After distilling off the aniline, the reaction mass is cooled to 2025 ° C, filtered and washed with cold water until neutral on a brilliant yellow paper. 14.8 g of the expected product are obtained, which amounts to a dye yield of 98%. When lavsan is dyed, the dye is greener in hue, the purity is cleaner than the type sample, the concentration is 100%. Example 2. The preparation of the dye is carried out analogously to example 1, with the difference that instead of distilling aniline, the reaction mass is treated with sulfuric acid to pH 4-6 at 80 ° C. 14.8 g of the expected product are obtained, which amounts to a dye yield of 98%. When dyeing lavsan, the dye in hue and purity corresponds to a type sample, the concentration is 100%. Example 3. In a three-necked flask with a capacity of 100 ml, equipped with a stirrer, a thermometer, a return water cooler and a feed funnel, 31.4 ml of water is loaded.

3.2 g of calcium carbonate ground and stirred for 20 minutes. Then, 5.37 g of aniline is charged, 0.2 g of NF dispersant. After 20 minutes of stirring, 7 g of 4-chloro-3-nitrobenzenesulfonyl chloride are loaded into this suspension at 20 ° C, heated for 15 minutes and stirred at this temperature for 5 hours. Then for 1 hour the reaction mass is heated to and allowed to stand for 10 hours. At the end of the exposure, the reaction mass is cooled to and hydrochloric acid is charged at this temperature to pH 4-6. The suspension of the dye is cooled to 30-40 0, filtered and washed.

9.6 g of the desired product are obtained, which constitutes a 97.3% dye yield.

In dyeing dacron, the dye in hue and purity corresponds to the typical oupasily, concentration of 100%.

Claims (2)

Claims for obtaining 2-nitro-1,1-diphenylamine-4-sulfanilide by reacting 4-chloro-3-nitrobenzenesulfonyl chloride with an excess of aniline in the presence of a condensing agent and a wetting agent, a product of naphthalene 2-sulfonic acid, with formaldehyde, at a temperature of 20 before, with the subsequent isolation of the target product, about tl and h aao0 n and in order to increase the yield of the target product, to improve the process technology, the carbonic acid or magnesite is used as a condensing agent 5 caustic. . Sources of information taken into account in the examination 1. The patent of Switzerland 323611, cl. 37th, 1957, 2. Technological regulations 0  497. Scientific and Technical Archive, D-406, p-1, No. 11555, 1973 (prototype).