DE2709864A1 - Tert. aliphatic amine prepn. - from satd. aliphatic alcohol and amine using highly selective catalysts - Google Patents

Abstract

Tert. aliphatic amines are produced by reacting 6-20C aliphatic alcohols and amines of formulae (I) or (II): NHR2 (I) or NH2R (II) (where R = Me or Et) in the presence of H2 and a catalyst contg. Cu II oxide and/or CrIII oxide and an alkali and/or alkaline each metal oxide. The reaction is effected in a stationary bed reactor at 160-350 degrees C/0-10 atmos. press. or in an autoclave equipped with stirring means at 80-160 atmos. press. High selectivity with almost quantitative conversions esp. in the case of alkyldimethyl- and alkylidiethylamines is provided. The catalysts have long life and show only at most 2% loss in activity over 1000 hrs. operation.

Description

Process for the production of tertiary ali-

phatic amines The invention relates to a method for the production of tertiary aliphatic amines from a saturated aliphatic Alcohol with 6 to 20 carbon atoms and an amine of the general formula NIiR2 or NH2R, where R represents a methyl or ethyl group, in the presence of hydrogen and a catalyst.

It is known from the Dutch application 65 07514, from primary or secondary amines to obtain an amine by reaction with a primary alcohol, the contains one more substituent on the nitrogen atom than the starting product. the However, yields and conversions are low and are, for example, for 2-octyldimethylamine at 41% and 64%.

From US Pat. No. 3,223,734 it is known to convert tertiary amines from secondary To produce amines and an alcohol. Example 5 is dodecylamine with dodecyl alcohol in present a copper chromite catalyst implemented. It result but only yields of 63.2% of tertiary amine. When implementing didecyl alcohol and dimethylamide, Rancy nickel is used as a catalyst; the yields Dimethyldodecylamine are also only in the range of 69.5% tertiary Amine.

The known methods have the disadvantage, only relatively bad Bring yields of tertiary amines.

So are the yields of amines, the init two methyl or ethyl and a longer chain alkyl group are substituted, below 70%, while Examples with amines with one methyl or ethyl and two longer-chain alkyl groups are substituted, completely absent.

The object of the present invention is a process for Production of tertiary amines with higher selectivities than the known processes with almost quantitative sales.

According to the invention, this is achieved in that the catalyst is copper (II) oxide and / or chromium (III) oxide and an alkali and / or alkaline earth metal oxide and the reaction at temperatures from 160 to 350 ° C in a fixed bed reactor at 0 to 10 atü or in a stirred autoclave at 80 to 160 atü.

When implementing an amine of the general formula NHR2, where R has the meaning mentioned, with one: n alcohol in the stirred autoclave can be the molar ratio Amine to alcohol 1 to i up to 5 to 1, preferably 1.5 to 1, and im Fixed bed reactor 1: 1 to 20: 1, preferably 2: 1 to 10: 1.

When reacting an amine with the general formula NH2R, where R has the meaning mentioned, with an alcohol in the Rüll autoclave the molar ratio Amine to alcohol 0.2 to 1 to 2.5 to 1, preferably 0.4 to 1 to 0.6 to 1, and im Fixed bed reactor 0.1: 1 to 2.0: 1, preferably 0.4: 1 to 0.6: 1.

The weight ratio when both metal oxides are present in the catalyst can be between 200: 1 and 1: 1 between copper (II) oxide and chromium (III) oxide.

The weight ratio of metal oxide to alkali and / or alkaline earth metal oxide can be 1 in 0.002 to 1 in 0.1.

Examples of alkali metal oxides are sodium oxide or potassium oxide.

For alkaline earth metal oxides, barium, strontium or magnesium can be mentioned will. A mixture of, for example, sodium oxide with barium oxide can also be used come into use.

The weight ratio in the presence of alkali and alkaline earth metal oxides can be 1 to 0.1 to 1 to 10 between alkali metal oxide and alkaline earth metal oxide.

The catalysts can be used either with or without a carrier will. If a carrier is used, the weight ratio of metal oxide to carrier should be used Be 1 in 0.3 to 1 in 30.

Examples of suitable carriers are aluminum oxide, bentonite, Aluminum silicates such as kaolin, cellite, etc., silicon oxides, zinc oxides and pumice stone. Depending on the carrier material, the specific surface can be between 2 and 500 m2 / g.

The reaction takes place in the presence of hydrogen, which, based on the molar throughput of alcohol, a minimum of 1 to 1, a maximum of 1 to 20 got to.

Suitable starting materials are primary saturated aliphatic alcohols with 6 to 20 carbon atoms; Examples are n-hexanol, n-octanol, n-decanol, n-dodecanol, n-exadecanol, n-octadccanol.

Secondary amines such as dimethylamine or diethylamine, or primary amines such as monomethylamine or ethylamine are used.

The isolation of the end products consists only in the separation the organic phase from the water phase formed and any distillation the organic phase.

The process according to the invention is characterized by high selectivities with almost quantitative sales, especially in the case of alkyldimethyl and alkyl diethylamines, the end. The catalysts have a favorable long-term behavior and only suffer minimal decrease in activity, usually at a maximum of 2% per 1000 hours of operating time lie.

Example 1 Preparation of dodecyldimethylamine in a stirred autoclave.

In a 300 ml stirred autoclave, a mixture of 66.6 g (0.357 mol) n-dodecanol (97%> together with 24 9 (0.535 mol) dimethylamine (98%) and 6.65 g Catalyst reacted at a temperature of 3000C. At the catalytic converter it is a mixture of approx. 25% CuO, approx. 1% Cr2O3, approx.

1% Na2O on kieselguhr. There is an initial pressure of approx. 60 atm a, which in the course of the reaction to approx.

80 atmospheres rise.

A crude product of the following composition is obtained: 80 to 82% Dodecyldimethylamine, 14 to 16% didodecylmethylamine, 1 to 2% dodecanol.

Example 2 Preparation of dodecyldimethylamine in a fixed bed tube.

In a fixed-bed tube charged with 63 g of catalyst (catalyst volume: 120 ccm) are 120 g / hour. n-dodecanol (97%) and 174 g / h. Dimethylamine (98%) is metered in. The catalyst is a mixture of approx. 25% CuO, approx. 1% Cr2o3, approx. 0.1% Na2O on kieselguhr. At the same time, 120 l / h. Hydrogen over the catalytic bed directed. The reaction temperature is 2400C.

After condensation, an organic phase with the following composition is obtained: 96% dodecyldimethylamine, 0.5% dodecanol, 1% didodecylmethylamine. at a conversion of 99t, the selectivity for dodecyldimethylamine is approx. 99%.

Example 3 Preparation of octyldimethylamine in a fixed bed tube.

In a fixed-bed tube charged with 96 g of catalyst (catalyst volume: 170 ccm) are 50 g / hour. n-octanol (98%) and 40 g / h. Dimethylamine (98t) is metered in. The catalyst is a mixture of approx. 25% CuO, approx.

1% Cr2O3, approx. 0.1% Na2O on kieselguhr. At the same time, 120 l / h. Hydrogen passed over the catalytic bed. The reaction temperature is 2200C.

After the condensation, an organic Pa of the following is obtained Composition: 96% n-octyldimethylamine, 0.4% octanol, 1.5% dioctymethylamine. at a conversion of 99%, the selectivity with respect to n-octyldimethylamine is 98%.

Example 4 Preparation of hexadecyldimethylamine in a fixed bed tube.

In a fixed-bed tube charged with 96 g of catalyst (catalyst volume: 170 ccm) are approx. 12 g / hour. n-hexadecanol (91%) and approx. 18 g / h. Dimethylamine (98%) dosed. The catalyst is a mixture of approx. 25% CuO, approx. 1% Cr203, approx. 0.1% Na2O on kieselguhr. An organic one is obtained after condensation Phase of the following composition: Approx. 93% n-hexadecyldimethylamine, approx. 1 ° hexadecanol, 1% i:) ihexadecylmethylamine. The conversion is approx. 98%.

Example 5 Preparation of dodecyldimethylamine in a fixed bed tube.

In a fixed bed tube charged with 130 g of catalyst (volume of Katalytbettes: 170 ccm) are 260.8 g of n-dodecanol (97.3%) and over 5 hours 400 g of dimethylamine (99.9%) are metered in. The catalyst is approx. 35% CuO on kaolin.

After the condensation, 299.6 g of the following organic phase are obtained Composition: 96.6% n-dodecyldimethylamine, 0.1% dodecanol, 0.7% didodecylmethylamine.

At a conversion of 99.98, the selectivity with respect to dodecyldimethylamine is 99.58.

Example 6 Preparation of didodecylmethylamine in a fixed bed tube.

In a fixed-bed tube charged with 63 g of catalyst (volume of Catalytic bed: 120 ccm) are 37 g / hour. n-dodecanol (97%) and 1.8 g / h. Methylamine (98%) registered. The catalyst is a mixture of approx. 25% CuO, approx. ^ 1% Cr203, approx. 0.1% Na2O on kieselguhr.

After condensation, an organic phase with the following composition is obtained: 11% n-Dodecylmethylamine, 57% didodecylmethylamine, 12% tridodecylamine and 17% unreacted n-dodecanol.

Example 7 Preparation of didodecyl / methylamine in a fixed bed tube.

In a fixed-bed tube charged with 85 g of catalyst (volume of Catalytic bed: 120 ccm) are 37 g / hour. n-dodecanol (97%) and 2.4 g / h. Methylamine (98% 9 entered. The catalyst is approx. 35% CuO on kaolin.

After condensation, an organic phase with the following composition is obtained: 2% n-dodecylmethylamine, 70% didoedcylmethylamine, 1% tridodecylamine and 21% not converted n-dodecanol.

Claims (7)

P a t e n t a n s p r ü c h e 1. Process for the production of tertiary aliphatic amines from a saturated aliphatic alcohol with 6 to 20 carbon atoms and an amine of the general formula NHR2 or Nt12R, where R is a methyl or Represents ethyl group, in the presence of hydrogen and a catalyst, thereby characterized in that the catalyst Kufter-IIoxid and / or chromium-III-oxide and a Alkali and / or alkaline earth metallo "id contains and the reaction at temperature of 160 to 350 ° C in a fixed bed reactor at 0 to 10 atmospheres or in a stainless steel autoclave up to 80 until 160 atm is executed. 2. The method according to claim 1, characterized in that in the reaction of an amine of the general formula NHR2, where R is the claim 1 has the meaning mentioned, with an alcohol in the stirred autoclave the molar ratio of amine to alcohol 1 to 1 to 5 to 1, preferably 1.5 to 1, and in the fixed bed reactor that Molar ratio of amine to alcohol 1: 1 to 20: 1, preferably 2: 1 to 10 1, is. 3 Method according to patent claim 1, d u r c h g e n n z e i c h n e t that in the implementation of an amine of the general formula NH2R, where R has the meaning given in claim 1, with Ci nem alcohol in a stirred autoclave the molar ratio of amine to alcohol is 0.2 to 1 to 2.5 to 1, preferably 0.4 to 1 to 0.6 to 1, and in the fixed bed reactor the molar ratio of amine to alcohol 0.1 to 1 to 2.0 to 1, preferably 0.4 to 1 to 0.6 to 1. 4. The method according to claim 1-3, characterized in that in the catalyst the weight ratio in the presence of both metal oxides between copper II-oxide and chromium-III-oxide is 200 to 1 to 1 to 1. 5. The method according to claim 1, 2 or 4 or 1, 3 or 4, thereby characterized that in the catalyst the weight ratio of metal oxide to alkali and / cdtr alkaline earth metal oxide is 1 in 0.002 to 1 in 0.1. 6. Method according to claim 1, 2, 4 or 5 or 1, 3, 4 or 5, characterized in that the weight ratio when present in the catalyst of alkali and alkaline earth metal oxide between alkali metal oxide and alkaline earth metal oxide Is 1 in 0.1 to 1 in 10. 7. The method according to claim 1, 2, 4, 5 or 6 or 1, 3, 4 5 or 6, characterized in that the catalyst is applied to a support The weight ratio used is methaloxide to carrier 1: 0.3 l: 30 amounts to.