RU2197473C2 - Method of preparing 1,4-bis(aminomethyl)cyclohexane - Google Patents

Abstract

FIELD: organic synthesis. SUBSTANCE: 1,4-bis(aminomethyl)cyclohexane in the form of aqueous solution is brought into reaction with liquid ammonia and hydrogen in presence of fine nickel/copper/chromium catalyst reduced with hydrogen at pressure 100 to 250 bar and temperature 150 to 250 C. EFFECT: simplified preparation technology. 3 ex

Description

 The invention relates to a method for producing 1,4-bis- (aminomethyl) cyclohexane.

 It is known to obtain 1,4-bis- (aminomethyl) -cyclohexane in a two-stage process from dicyanobenzene (see German patent application 3003730). In a first step, dicyanobenzene is catalytically hydrogenated to 1,4-bis (aminomethyl) benzene, which is then catalytically hydrogenated to 1,4-bis (aminomethyl) cyclohexane. The disadvantage of this method is that the starting compounds must be obtained using hydrogen cyanide.

 Synthesis without the use of cyanides was first proposed based on 1,4-bis-hydroxymethylcyclohexane (US Pat. No. 3,134,570), but it is technically unsatisfactory.

 The objective of the invention is to develop a simple method for producing 1,4-bis- (aminomethyl) -cyclohexane.

The problem is solved in a method for producing 1,4-bis (aminomethyl) cyclohexane by the interaction of 1,4-bis (hydroxymethyl) cyclohexane with ammonia and hydrogen in the presence of a nickel-containing catalyst, at temperature and pressure, due to the fact that 40 - 80- wt.% - an aqueous solution of 1,4-bis (hydroxymethyl) cyclohexane with liquid ammonia and hydrogen and in the presence of a nickel / copper / chromium micrograined catalyst reduced with hydrogen, at a pressure of from 100 to 250 bar and at a temperature of from 150 to 250 ^o FROM.

 The microgranular catalyst consists of 60 to 50 mol.% Nickel, 14 to 17 mol. % copper and 26 - 33 mol.% chromium.

 This nickel / copper / chromium catalyst is prepared by mixing the catalytic components in the form of a powder, which has a normal grain size in the range from 0.001 to 200 microns.

The interaction is carried out at a temperature of from 150 to 250 ^o C and a pressure of from 150 to 250 bar, if necessary, in an atmosphere of inert gas (eg nitrogen).

Example 1
The method is carried out in a once-through reactor with a fixed catalyst bed.

The reactor is filled with 100 cm ^{3 of a} catalyst consisting of 57 mol.% Nickel, 14 mol.% Copper and 29 mol.% Chromium obtained by mixing the powders of the catalytic components, and restore using a stream of hydrogen.

Reagents are fed hourly in portions of 100 l of hydrogen, 100 cm ^{3 of} liquid ammonia and 20 cm ^{3 of a} 50% aqueous solution of 1,4-bis (hydroxymethyl) cyclohexane. During the reaction, a temperature of 190 ^{° C. was} maintained at a pressure of 200 bar.

 After removing water and ammonia from the mixture, 9.9 g of product per hour are obtained containing 60 weight. % 1,4-bis- (aminomethyl) cyclohexane; and 20.3% by weight 1,4-bis- (hydroxymethyl) cyclohexane.

 The conversion is 80.1% and the selectivity for the formation of 1,4-bis- (aminomethyl) cyclohexane is 74.5 mol.%.

Example 2
The method is carried out in the presence of a catalyst, as described in example 1.

The reagents are fed in controlled portions per hour, 100 l of hydrogen, 100 cm ^{3 of} liquid ammonia and 13 cm ^{3 of a} 70% aqueous solution of 1,4-bis (hydroxymethyl) cyclohexane. The temperature is 190 ^o C and a pressure of 200 bar. After removing water and ammonia in an hour, 8.8 g of product are obtained, which is a mixture of 71.4 wt.% 1,4-bis- (aminomethyl) cyclohexane and 11.2 wt. % 1,4-bis- (hydroxymethyl) cyclohexane. The degree of conversion is 89.2% and the selectivity to 1,4-bis (aminomethyl) cyclohexane is 78.3 mol%.

Example 3
The method is carried out analogously to example 1. 100 cm ^{3 of a} powdered catalyst containing 50 mol.% Nickel, 17 mol.% Copper and 33 mol.% Chromium are loaded into the reactor.

The reagents are fed in 100 L hydrogen, 100 cm ^{3 of} liquid ammonia and 13 cm ^{3 of a} 50% by weight aqueous solution of 1,4-bis (hydroxymethyl) cyclohexane added once per hour. During the process, the temperature is 190 ^o C and a pressure of 200 bar. After removal of water and ammonia, a portion of 6.4 g of product is obtained every hour, which contains 53% by weight of 1,4-bis (aminomethyl) cyclohexane and 17.8% by weight of 1,4-bis (hydroxymethyl) cyclohexane . The conversion of 1,4-bis (hydroxymethyl) cyclohexane is up to 82.6% and the selectivity for the formation of 1,4-bis (aminomethyl) cyclohexane c is 63.5 mol%.

Claims (1)

The method of obtaining 1,4-bis- (aminomethyl) cyclohexane by the interaction of 1,4-bis- (hydroxymethyl) cyclohexane with ammonia and hydrogen in the presence of a nickel-containing catalyst at temperature and pressure, characterized in that they are reacted with 40-80-weight. % aqueous solution of 1,4-bis- (hydroxymethyl) cyclohexane with liquid ammonia and hydrogen in the presence of a nickel / copper / chromium micrograined catalyst reduced with hydrogen, at a pressure of 100-250 bar and at a temperature of 150-250 ^o C.