SU1606183A1 - Catalyst for nitrizing diphenylamine to n-nitrozodiphenylamine - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular the use of iron pentacyanide complexes of the general formula NA _2-4 [FE (CN) ₅ X], where X-NH ₃ , H ₂ O, N ₂ H ₄ , NO ₂ , NO, as a catalyst for nitrosation of diphenylamine to N-nitrosodiphenylamine in acidic aqueous-alcoholic solutions using nitric oxide as the nitrosating agent. In this case, diphenylamine conversion of 94-99% is achieved in 2 hours of work (instead of 5 hours without a catalyst), which indicates a high catalyst activity and allows an increase in the productivity of the process 2.2-2.4 times and eliminates laborious and energy-intensive cooling stages. the reaction mixture. 1 tab.

Description

This invention relates to catalysts for the nitroscopic diphenylamine to N-nitrosodophenylamine,

The purpose of the invention is to increase the activity through the use of iron pentacyanide complexes of the general formula Na .. Fe (CN) jf where X is NH%,,, 1-S ,,, NO, as a catalyst for the process of nitrosation of diphenylamine in L- nitrosodiphenylamine in acidic alcoholic solutions using nitric oxide as an nitrotic agent. J-, These complexes were previously used as nitrosation catalysts. not applied.

With

e p

Into the reactor capacity

500 liters, equipped with a mixing device. . put a solution of 25 g

diphenylamine in 300 ml of ethanol and with stirring a solution of i: pentacyanide complex added. Naj CFe (CA) 5% of water and 5 ml of concentrated hydrochloric acid (density 1.19). The catalyst concentration is 10 mol / L. With continuous stirring at room temperature, the solution passes through gaseous nitric oxide at a rate. 2 l / h After 2 h, the precipitated N-nitrosodiphenylamine is filtered off, washed 2-3 times with water and then dried under vacuum. 27.9 g of N-nitrosodiphenylamine are obtained (yield 95.3%), melting point 66.5-67 ° C. The purity of the product according to electron spectroscopy is 99.5%.

Characteristics of the process when using different pentacyanide iron complexes as kata,: (ia o o:

00 with

congestion given in the table. The process of obtaining N-nitrosodiphenylamine is periodic.

In the case of a fivefold repeated test of the process with the same catalytic solution (i.e., 10 hours of operation), the activity of the catalysts does not decrease, and the selectivity does not change.

Carrying out the process of obtaining N-nitrosodiphenylamine using iron pentacyanide complexes as a catalyst makes it possible to achieve a diphenylamine conversion of 94-99.5% in 2 hours,

carrying out the process according to a known method (without a catalyst) for 2 hours does not result in N-nitrosodiphenylamine, since the process is carried out for a period of time. 5 hours (acidification of the reaction mixture is carried out for 3 hours by slowly adding sulfuric acid while cooling).

(. Thus, diphenylamine conversion of 99% is achieved in a known method without using a catalyst for 5 hours of operation: the same conversion using the proposed catalyst is achieved in 2 hours of operation, which indicates a high catalyst activity and allows to increase the productivity of the process in 2.2-2.4 times.

In addition, the use of iron pentacyanide complexes as a catalyst makes it possible to refuse

Claims (1)

15 laborious and energy-intensive stage of cooling the reaction mixture. Claim 1 Application of iron pentacyanide complexes of the general formula (CN where X is STTC, H.,, NO ,, NO, c. Quality of catalyst for nitrodation of diphenylamine in N-nitrosodiphenyl-amine Characterization of N-nitrosodiphenylamine production processes Known process a,) 5NH, 3 (CN) jNO (СЯ) 5НгО Na, Fe (CN) 5NjH4l) 5NOj NaNO. 15-30 lUO: i-PrOH 99.9 60:40 The process using the proposed catalyst About About About About ABOUT 99.3