RU1825357C - Method for producing nitromesitylene - Google Patents

Abstract

Use of the invention: as an intermediate in the synthesis of dyes or drugs. SUMMARY OF THE INVENTION: nitromesitylene product, yield 81.4%. Reagent 1: mesitylene. Reagent 2: smoke nitric acid. Reaction conditions: in the presence of a catalyst - activated ascanite-bentonite in a medium of carbon tetrachloride or hexane at 20-25 ° C, a molar ratio of reactant 1 to reactant 21: 1.95, mass ratio of reactant 1 and catalyst 1: 3.1 . 1 tab.

Description

The invention relates to a method for producing nitromesitylene, which is used as an intermediate in the synthesis of acid anthraquinone dyes and drugs.

The purpose of the invention is to increase the efficiency of the method of producing nitromesitylene and increase the yield of the target product.

This goal is achieved by nitration of mesitylene with fuming nitric acid in the presence of a solid acid catalyst - ascanite-bentonite activated at room temperature in an organic solvent (hexane, carbon tetrachloride) at a molar ratio of mesitylene: HMO3. equal to 1: 1.95; and a weight ratio of mesitylene inhibitor. equal to 1: 3.1. This achieves a high yield of nitromesitylene (90%), high selectivity of mononitration with respect to dinitration (12-17: 1), (see examples 1,3 and 16 compared with example

2, when nitration was carried out without Ascanite-bentonite). The content of the basic substance in the nitration product reaches 90.5%, mesitylene remains 4.3%, dinitromesitylene forms only 5.2%.

Ascanite-bentonite, as a catalyst for the nitration of mesitylene, can be used up to 5 times, although there is a tendency to decrease its activity and decrease the ratio of mono- and dinitroproducts (see Examples 12-15).

Example 16 shows the feasibility of using a return MSC for the recovery of nitration products, in addition, this experiment was carried out on batches increased by 10 times.

The proposed method of nitration of mesitylene has the following significant differences from the prototype method:

carrying out the process in the presence of ascanite-bentonite as a solid catalyst;

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conducting a nitration reaction at room temperature (20-25 ° C);

carrying out the process in hexane and carbon tetrachloride as organic solvents.

PRI me R 1. To a suspension of 5.0 g of Ascanite-bentonite (OST 113-12-86-82), dried at 150 C for 12-16 hours (moisture 1-2%), in 50 ml of SCS while stirring for 10-15 minutes, 1.15 ml (2.70 10 mol) of fuming nitric acid (COB - 95.2%) was added. Stirring was continued for another 5 minutes. Then 1.6 g (1.35 mol) of mesitylene were added to the stirred mixture at the same time, while the temperature of the reaction mixture rose by 5–6 ° C. Gradually, over the course of 30–40 min, the temperature of the mixture dropped to room temperature (20–25 ° C). C), stirring at this temperature was continued for 5 hours after the addition of mesitylene. After the exposure was completed, Ascanite-bentonite was filtered off and washed with CCI 4 (ml) to recover nitration products. The resulting solution was washed with water (2x50 ml) and dried over potash or anhydrous sodium carbonate. After removing the solvent on a rotary evaporator, 2.1 g of product were obtained, the composition of which is shown in the table by GLC.

Example 2. To a stirred mixture of 1.15 ml (2.70 mol) of fuming nitric acid (COB - 95.2%) in 40 ml of CCM was added in portions over the course of Yumin 1.6 g (1.35 -10 mol) of mesitylene in 10 ml of SCC. An increase in the temperature of the reaction mixture by 5 ° C was observed, then within 30 minutes the temperature of the mixture dropped to room temperature. Stirring was continued for 5 hours. The reaction mixture was treated as in example 1 after filtration, 2.09 g of product was obtained, the composition is shown in the table.

Examples 3-5. Mesitylene was nitrated as in Example 1, using hexane, chloroform and methylene chloride as solvents in the nitration.

Examples 6-9 illustrate the effect of a change in the mesityl: HNOa molar ratio and the mesityl: catalyst weight ratio on the yield of nitromesitylene and the selectivity of mononitration with respect to dinitration.

Examples 10-11. Mesitylene nitration was carried out as in example 1, but stirring after adding mesitylene

carried out, respectively, at 15 ° C and 30 ° C.

Examples 12-15 show the possibility of sequential use of ascanite-bentonite the 2nd, 3rd, 4th and 5th time after preliminary drying it at 150 ° C to a moisture content of 1-2%.

Example 16. To a suspension of 50 g of ascanite-bentonite (moisture 1.5%) in 250 ml of SCS, 11.5 ml (2.70 mol) of fuming nitric acid (COB - 95.2%) was added over 15 minutes with stirring. The mixture was stirred for another 5 minutes, then 16 g (1.35 -10 1 mol) were added to this mixture in one go

mesitylene. After the addition of mesitylene, the reaction mixture was cooled with ice-water for 30 minutes so that the temperature of the mixture did not rise above 35 ° C. Then, cooling was stopped and stirring of the reaction mixture was continued at room temperature for 5 hours from the moment mesitylene was added. At the end of the exposure, the reaction mixture was treated as in Example 1, cc for extracts

nitration products 600 ml of refluxing SCC (ml), 22.0 g of product are obtained, the composition is shown in the table.

Thus, a convenient and effective method was proposed for nitration of mesitylene with fuming nitric acid in the presence of an affordable and cheap solid catalyst, ascanite-bentonite in an organic solvent (hexane, carbon tetrachloride) at room temperature. A high nitromesitylene yield (90%) and a high mono-dinitration ratio (12-17: 1) are achieved with a high degree of conversion of the starting mesitylene (95%). The proposed nitration method does not require water-alkaline treatment of the reaction mixture after nitration and avoids the formation of a large amount of acid effluents, which significantly improves the environmental parameters of the process.

Claims (1)

SUMMARY OF THE INVENTION Method for producing nitromesitylene by nitration of mesitylene with fuming nitric acid in the presence of a solid catalyst, characterized in that ascanite-bentonite activated is used as a solid catalyst and the process is carried out at a mesitylene: aeroic acid molar ratio of 1: 1.95. and a mesitylene: catalytic mass ratio of 1: 3.1. at 20-25 ° C in an environment of carbon tetrachloride or hexane.