JPS6048952A - Preparation of dimethylhexamethylenediamene - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a raw material for agricultural chemicals, drugs, and transparent nylon in high yield in high selectivity, by hydrogenating dimethyladiponitrile by the use of a Raney coable catalyst, carrying out purification easily. CONSTITUTION:Dimethyladiponitrile is hydrogenated at 80-160 deg.C at 20kg/cm<2>G H2 hyrogen partial pressure for >=1hr by the use of water slurry of a Raney cobalt catalyst obtained by developing a Raney cobalt alloy in NaOH, catalyst is separated from the reaction solution by a filter, and high-purity dimethylhexamethylenediamine is purified by distillation, etc.

Description

Detailed Description of the Invention The present invention is a method for hydrogenating dimethyladiponilyl (hereinafter referred to as DMADN) to produce dimethylhexamethylene diamine (hereinafter referred to as DMHMD) with high yield and high selectivity. It is related to.

DMHMD is useful as a raw material for agricultural chemicals and medicines, and is also an important substance as a raw material for transparent nylon.

A conventional technique for producing DMI (MD) from DMADN is a method in which DMADN is hydrogenated in the presence of Raney nickel [Tetrahedren 1ette].
r.

1970 P-3791-4] has been proposed, but there is no detailed explanation of this production method, and it is only stated that hydrogenation is carried out using Raney nickel, so the detailed production method is not known, but the reaction yield is 56% in DMHMD, dimethylhexamethyleneimine (hereinafter abbreviated as DMHMI)
Although the reaction yield is stated as 9%, it is not sufficient for an industrial production method.

The present inventors have conducted intensive research to develop a method that can achieve a high yield of DM)IMD and can be easily implemented industrially. DM can be easily produced in extremely high yield by hydrogenation using
We have discovered that it is possible to manufacture HMDs.

An object of the present invention is to provide a method for producing MHMI in which the yield of DMHMD is high and is industrially advantageous.

The method for producing DMHMD of the present invention, which achieves the above object, is characterized by hydrogenating dimethyladiponitrile in the presence of a Laneco Malto catalyst.

The present invention will be explained in more detail below.

In the present invention, it is necessary to use a Raney-Connolt catalyst as the catalyst. As the Raneyco-Cert catalyst, for example, a Raneyco-Cert alloy developed with NaOH can be used.

The amount of catalyst is 0 in weight ratio to the charged DMADN.
．． If the amount is 0.004 or more, the reaction will not proceed.If the amount is less than 0.004, the reaction will not proceed.There is no limit to the amount of catalyst, but it is naturally limited due to catalyst cost and stirring.

In the present invention, a hydrogenation reaction can be carried out using a substantially solvent-free liquid composition consisting of DMADN as a raw material and a Raney-Connolt catalyst.

The reaction temperature is preferably 80°C to 160°C. At temperatures below 80°C, the reaction does not proceed, and at temperatures above 160°C, the reaction yield decreases.

The reaction pressure consists of approximately hydrogen partial pressure, and the partial pressure is 2
0 K17cm" G is required. 20 Kg/
cyt"G or less, the reaction does not proceed.

The reaction time is determined depending on the amount of catalyst, reaction temperature, and reaction pressure, but usually one hour or more is sufficient.

The reaction solution may be stirred as long as it disperses the catalyst uniformly in the reaction solution.

The reaction method is either a batch method in which the raw materials are charged at once and the reaction is carried out until DMADN is consumed, or a batch method in which the raw materials are continuously charged and the reaction is carried out until the DMADN is consumed.
There are continuous methods that continuously extract the product.

DMHMD can be obtained from the reaction solution by a conventional method. For example, after separating the catalyst from the reaction solution using a filter, etc., it is purified by distillation to obtain high-purity DMHM.
This is the method to obtain D.

As detailed above, by applying the present invention, 1) DMHMD can be obtained in high yield. 2) Since almost no by-products are produced and the reaction solution is essentially only the main reaction product, DMHMD can be purified very easily. Effects such as this were brought about.

Hereinafter, the present invention will be explained in more detail using examples.

Example 1 A commercially available Laneco/? Aqueous slurry o, sy (Raneco/Alto catalyst) obtained by developing Ruto alloy (Co:AI weight ratio = 50:50) with NaOH and washing with water
, 25y, water o, ss y) and DM) IMD 40
After charging P, the air in the autoclave was first replaced with nitrogen, then with hydrogen, and hydrogen was introduced to 45 K17 cm"G. (The reaction pressure is kept constant.) Next, the temperature is raised by heating with a heater, and at the same time the inside of the reactor is rotated at a rotation speed of 11,000 using a stirrer.
Stir with RP. The set temperature reaches 140 in about 25 minutes after the temperature rise starts.
When the temperature reached ℃, the reaction was started. During the reaction, hydrogenation was carried out while adjusting the temperature and pressure to be maintained. Two hours after the start of the reaction, the supply of hydrogen was stopped, the autoclave was cooled, and the reaction was stopped. After the completion of the reaction, the reaction results were determined from the weight measurement of the reaction solution and the analysis results using a gas chromatograph: conversion rate of HDMADN was 100%, DMHMD.
17) Selection 5- The yield was 91.2%, and the selectivity for DMHMI was 8.4.

Example 2 Water slurry of Raneyconort catalyst of Example 1〇, 8y
From 2.11 (Raneikonomolt 1.OF, water 1.1
1) The hydrogenation reaction was carried out in the same manner as in Example 1 except for the following changes.The reaction result was 1 in terms of conversion rate of DMADN.
00%, DMHMD selectivity 91.0%, DMHMI
The selectivity was 8.5.

Example 3 A hydrogenation reaction was carried out in the same manner as in Example 2, except that the hydrogenation reaction temperature was changed from 140°C to 150°C and the reaction time was changed from 2 hours to 30 minutes. The reaction result was 100 in terms of conversion rate of DMADN. %, selectivity of DMHMD is 91.1%, D
The selectivity of MHMI was 8.3%.

Patent applicant: Asahi Kasei Industries, Ltd. 6-

Claims (1)

[Claims] A method for producing dimethylhexamethylene diamine, which comprises hydrogenating dimethyladiponitrile in the presence of a Raneyconolt catalyst.