SU1695976A1 - Catalyst for producing n-nitrosodiphenylamine from diphenylamine - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular the use for the nitrosation of diphenylamine in N-nitrosodiphenylamine of a catalyst of the total fi l Na2-3 Fe (CN) 5X, where X-YH3, H2O, OH, N0a which improves the productivity of the process on N-nitrosodiphenylamine 1.3-1.4 times with conversion up to 99%, which is achieved in -1.5 hours versus 2 hours in the known case. 1 tab.

Description

This invention relates to catalysts for the nitrosation of diphenylamine to N-nitrosodiphenylamine, which finds use as a stabilizer in the manufacture of rubbers, plastics, is an intermediate of organic synthesis.

A method of producing N-nitrosodiphenylamine by nitrosing diphenylamine using alkali metal or ammonium nitrites as nitrosating agents is known, and the reaction is carried out in the presence of an acid in an organic solvent medium or in aqueous-organic media, for example, a method for producing N-nitrosodiophenylamine by nitrosation of diphenylamine nitrites in acidic water-alcohol solutions. The yield of the target product reaches 99.3% with a process time of 5 hours. Capacity 6-10 2 kg / lh 1.

The disadvantages of this method include the long duration of the process, as well as the need to cool the reaction mixture.

c. It is known to use as a catalyst for the nitrosation of diphenylamine in N-nitrosodiphenylamine pentacyanide complexes of iron (II) of the general formula Na2-4 Fe (CN) sX, where X is NHS, H2O, N2H4, NO2, NO.

This catalyst makes it possible to achieve an intensification of the process of nitrosation of diphenylamine by reducing the time of nitrosation, and also to eliminate the need to cool the reaction mixture 2 and 3.

However, it does not possess sufficiently high activity, does not ensure the achievement of an increased yield of N-nitrozodiphenylamine, and does not allow a substantial increase in the productivity of the nitrosation process.

BUT

I ate

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The aim of the invention is to increase the activity of the catalyst. 1 The above objective is achieved by using the pentacyanide complex of iron (III) of the general formula Na2-3 Fe (CN) sX, where X is MH3, H2O, OH, NO2, as a catalyst for the diprosylamine nitrosation in M-nitrosodiphenylamine. The essence of the invention is as follows.

The nitrosation process using the proposed catalyst is carried out in a water-alcohol solution, ethanol is chosen as a flirt, with a ratio of iodine: ethanol from 10:90 to 40:60, at room temperature without the use of cooling the reaction mixture. Gaseous nitric oxide is used as a nitrosating agent, which is taken in an amount of 1.0-1.2 from the stoichiometric amount. When the amounts of nitric oxide are lower than the stoichiometric, the completeness of nitrosation is not ensured, and with greater than 1.2 from the иthiometric, the yield of the product does not increase. The concentration of the catalyst - the pentacyanide complex of iron (III) co- = 10–5–10 3 mol / l. The process is carried out in the presence of hydrochloric acid, the concentration of which in the reaction mixture 2.5-S 2 is 2.5-10.

PRI me R 1.

An OOO ml, equipped with a mixing device, is placed a solution of 50 g of diphenylamine in 300 ml of ethanol and a solution of 100 mg of pentacyanide iron (III) complex (CN) sH20 in 100 ml of water and 10 ml of concentrated hydrochloric acid {density 1.19 ). With continuous stirring, a gaseous mixture of nitrogen is passed through the solution at a rate of 5.33 l / h.

mol / l. Into the reactor capacity

After 1.5 hours, the precipitated N-nitrosodiphenylamine is filtered off, washed 2-3 times with water and then dried in vacuum at 40 ° C. Get 56,4 g of M-nitrosodiphenylamine

(yield 96.3%), so pl. 66.5-67 ° C. The purity of the product according to electronic spectroscopy is 99.5%. Productivity 9, kg / lh.

PRI mme R 2. The process is carried out analogously to example 1, but the iron (III) (CN) 5H20 complex takes 500 mg. 57.6 g of N-nitro-zdiphenylamine are obtained (yield 98.4%). Productivity is 9,6 kg / l - h.

The characteristics of the process when using various pentacyanide complexes of iron (III) as catalysts in comparison with the use of complexes of iron (II) are given in the table.

As can be seen from the table, the use of iron (III) pentacyanide complexes as catalysts significantly increases the productivity of the process for the production of N-nitrosodiphenylamine — by 1.3–1.4 times as compared with iron (II) complexes. Conversion of diphenylamine is 99% achieved using iron (III) complexes in 1.5 hours instead of 2 hours in the prototype. The process is periodic, with its repeated operation with the same catalytic

with a solution for at least 5 times (i.e. 7.5 hours of operation), the yields of N-nitrosodiphenylamine are not reduced.

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Claims (1)

Invention Formula The use of the pentacyanide complex of iron (II) of the general formula Na2-3 Fe {CN) 5X, where X is MNH, H20, OH, M0g, as a catalyst for the nitrodation of diphenylamine into N-nitrosodiphenylamine.