SU1402598A1 - Method of producing sodium 2,4-dinitrobenzene sulfonate - Google Patents

Abstract

The invention relates to sulphonic acids, in particular to the preparation of sodium 2,4-dinitrobenzene sulphonate, which is used in the manufacture of acid dyes and azo dyes. The goal is to increase the yield of the target product and intensify the process. Obtaining the target product are from 2,4-dinitrochlorobenzene and sodium sulfate in an aqueous medium with heating and in the presence of a catalyst (CG). As the latter, monoalkyl ether of polyethylene glycol based on fatty alcohols of the formula: CpHjn, (CHjCHjO) 2 o H is used, where n is 16-20. The use of this CG increases the yield of the target product by 15%, reduces the duration of the process to 3 hours.

Description

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The invention relates to an improved process for the preparation of sodium 2,4-dinitrobenzene sulfonate sodium, which finds use as an intermediate product in the manufacture of acid dyes and azo dyes.

The aim of the invention is to increase the yield of the target product and to intensify the process, which is achieved by sulphurization of 2,4-dinitrochlorobenzene sodium by sulphonation as a catalyst for monoalkyl fat of polyethylene glycol based on fatty alcohols of the formula CnHjn4i (CH2CH20) 2o.H, where n 16-20 .

 Example 1. 10.1 g (0.05 mol) 254-dinitrochlorobenzene, 15 ml of water and 1 g: monoalkyl ether polyethylene-- Glycol of the formula Cf, Hr, n, (), N, Where n 16-20, is heated at stirring to 60-65 ° C, at this temperature type is added in 2 hours for 2 hours.

Mass of solution 10 g

 25

in 20 ml of water, maintaining a pH of 8.5-9 by adding water. After the addition of the total solution, the solution is then reduced to 60–65 seconds for 1 h. The resulting Na-salt 2,4-dinitrobenzene sulfonic acids salt out 7.5 g of HaCl, dried at 90–100 ° C. T2.7 g is obtained (95 , 5% of the theory.) Sodium 2,4-dinitro-4-benzenesulfonate. ; Example 2. The experiment was carried out in an analogous manner to Example 1, but the addition of a solution of Na2Sj05 was carried out for 4 hours, then cooled and salted out; nagri 4-dinitrobenzenesulfonate, 4 | Thin, dried at 90-100 ° C. 12.59 g (94.5% of theor.) 2,4-Ndinitrobenzene sulfonate sodium are obtained.

Example 3 (prototype). 20 parts of 2,4-dinitrochlorobenzene - mixed with 30 parts of water and 2 parts of dodecylbenzenesulfonic acid salt added, and 2 parts of () (CgH40)

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 (Cll2CH20) / i5 N. The f-temperature is raised to and the pH of the mixture is maintained at 8-8.5 by the addition of 40% NaOH solution throughout the feed time of 13 hours. 40% solution of NaNOz for 10 hours with vigorous stirring of the mixture. At the end of the reaction, the pH of the mixture was adjusted to 3 by adding concentrated hydrochloric acid, then 15% NaCl was added by volume of the mixture. 21.6 h are obtained. Na salts of .2,4-dinitrobenzene sulfonic acid, which is 80% of theory.

Thus, the use of the proposed catalyst increases the yield of the target product by 15% compared with the prototype, reduces the process time to 3 hours (in the prototype, the reaction time is 10 hours).

In addition, in the proposed method, the wastewater, provided that a method for purifying them from nitro compounds arises, can be biologically purified from the catalyst, since the proposed catalyst is a mild surfactant and is easily biodegradable, its degree of decomposition is about 90%.

Claims (1)

Invention Formula The method of producing sodium 2,4-dinitrobenzene sulphonate by reacting 2,4-dinitrochlorobenzene with sodium sulphites in an aqueous medium with heating and in the presence of hydroxyethyl compounds as a catalyst, so that increasing the yield of the target product and intensifying the process; monoalkyl ether of polyethylene glycol based on fatty alcohols of the formula SpNgn- (H, where n is 16-20) is used as a catalyst.