DE2358355A1 - PROCESS FOR PRODUCING 1,3DIAMINO-2,2-DIMETHYLPROPANE - Google Patents

Description

Oberhausen-Holten, November 20, 1973 RSk / Sei - E 1799

Poihrchemie Aktiengesellschaft, Oberhausen-Holten

Method of making 1,3 ~ diamino-2,2 dimethylpropane

It is known to produce diamines from two-part alcohols, for example ethylenediamine is obtained according to US Pat. No. 3,137,730 from ethylene glycol and ammonia to cobalt and nickel as well Copper-containing catalysts «The manufacture of hexamethylenediamine from 1,6-hexanediol, ammonia and hydrogen on nickel or cobalt containing Ifefcalysatoren in U.S. Patent 3,268,588.

According to DT-OS 1 955 263, polyalcohols, in particular various glycols, by converting ammonia on a cobalt, nickel or copper containing catalyst to form the corresponding amines are implemented.

DT-AS 1 172 268 contains a process for the production of diamines from dihydric aliphatic alcohols and ammonia in the presence of hydrogen at a temperature of 150 to 30O ⁰ C and a pressure of at least 10 atm with nickel-containing catalysts. :

Not all dialcohols can be converted by the well-known pressure ammonolysis, since the bilateral reaction on α, ^ -diols is not subject to a uniform reaction mechanism. Depending on the position of the two hydroxyl groups to one another

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one different reaction products. From propane-1,3-diol, as was shown by our own experiments with nickel catalysts, the diamine could only be obtained in amounts below 1% , since allyl alcohol evidently occurs as an intermediate through β-elimination of a hydroxyl group is converted to primary and secondary propylamine. In addition, considerable amounts of hydrocarbons are produced.

With neopentyl glycol, which is more stable than propane-1,3-diol, no dehydration can occur through ß-elimination, however, by dehydrating a hydroxymethyl group to Aldehyde group hydroxypivalaldehyde are formed. Furthermore, aldol cleavage to formaldehyde and isobutyraldehyde was possible expects x ^ earth. The resulting fragments can then with the gases ammonia and hydrogen present in the reaction medium by reducing amination to methylamine and convert isobutylamine.

From the observations and considerations presented above, it is likely that the implementation of Neopentyl glycol to the corresponding diamine by pressure ammonolysis has not yet been attempted. Rather, this diamine was previously obtained by reacting with acetone Nitromethane to 2,2-dimethyl-1,3-clinitropropane and hydrogenation of the dinitro compound (S. JACS 71, 3. 3249 [1949j)

Since neopentanediamine is, among other things, a valuable intermediate for the production of polyurethanes, a technically simple process for its production from the easily accessible neopentyl glycol was desired. It has now surprisingly been found that the side reactions described above largely favor diamine formation

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can be pushed back, so that this compound using special catalysts in compliance with "certain Process conditions made directly from neopentyl glycol v / can earth.

The invention consists in a process for the preparation of dianines from dihydric aliphatic alcohols and ammonia in the presence of hydrogen "at a temperature of 150 to 300 ° C and a pressure of at least 10 atm in the presence of a nickel-containing catalyst, which is characterized in that one, ammonia and hydrogen "teaches 220 to 300 ⁰ C with a catalyst in contact, the 23" for the production of l, 3-diamino-2,2-dimethylpropane ITeopentylglykol contains up to 60 Gew./j deposited on a support material ITickels.

Maintaining a temperature of 240 to 260 ^° C. has proven to be advantageous.

Particularly suitable are catalysts which, in addition to nickel, optionally May contain 16 to 40 wt.% Chromium, in particular present as CrpO ^ in the catalyst. As a carrier Appropriately kieselguhr added to the catalyst. Hr can next SiO ~ still contain aluminum oxide and magnesium oxide.

The molar ratio OH: NH- is not critical. It is

P.
For example, it is known from the literature that you can work with an OH: NH, ratio of 1: 100 ', and that even higher ΝΗ -, - amounts can be used.

In the method according to the invention, a molar one is expedient Ratio OH: NH, from 1: 4 to 1 i 40 upright

keep. A molar ratio of OH of 1: 6 to 1:20 is particularly favorable.

BATH ORIGINAL

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With the process according to the invention, yields of 1,3-diamino-2,2-dimethylpropane of more than 50% are obtained, so that hereby a possibility has been created to convert the technically valuable diamine into economically interesting ones To receive quantities.

The implementation can be carried out in any way are »whereby the reactants are allowed to react with one another discontinuously or continuously can.

The following examples serve to illustrate the invention.

example 1

800 g of neopentyl glycol and 80 g of a commercially available nickel catalyst (RCH catalyst 55/10 TS) were placed in a 10 l steel autoclave. The catalyst consists of 55% nickel and AlpO, and kieselguhr as the carrier material. It contains 10 parts Al ₃ O ₃ and 50 parts kieselguhr per 100 parts of nickel. It was first heated to 70 ° and then 1600 g of ammonia were introduced into the steel vessel by means of a pressure pump. In addition, 20 atmospheres of hydrogen gas were injected and the mixture was heated to 24-5 ° for four hours while stirring vigorously. An operating pressure of 100 atmospheres was established.

While the pressure reactor was still cooling and the gas phase was slowly being let off, the contents of the autoclave were filtered through a Seitz filters. Gas chromatographic analysis of the filtrate had the following result:

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Product content in percentage of area

Advance 15.7

l ^ -Di
propane

_{& 2} propane *

Neopentyl glycol 5.1

Lag 1.8

Thus, with a conversion of 9 ^, 9%, based on neopentyl glycol, 71 »1 % of the desired 1,5-diamino-2,2-dimethyl-propane were obtained.

54-8 g of the diamine in the boiling range of 154-156 could then be separated from the crude filtrate by preliminary and subsequent peeling distillation at normal pressure. This amount corresponds to 73 »7% of the 1 _i 3-diamino-2,2-dimethylpropane theoretically expected from the converted neopentyl glycol.

Example 2

As in Example 1, 800 g of neopentyl glycol were reacted in a 10 l steel autoclave in the presence of 80 g of a commercially available chromium-nickel catalyst (ROH catalyst 52/35 TS). The ^ alysator consists of 52% nickel, with 100 parts by weight of nickel accounting for 30 parts by weight of Ohrom-III-oxide. Diatomaceous earth is used as the carrier in an amount of 50 parts per 100 parts of nickel. Here too, 20 atmospheres of hydrogen gas are pressed in to activate the catalyst and heated to ^{0 for two hours}

The composition of the crude film separated from the catalyst entered it has the following composition;

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Product content in percentage of area

Leader . 11.6

1,3-diamino-2, ^ dimethyl- ^ ₀ ?

propane - * *

l-amino-3-hydroxy-2,2-dimethyl pi « propane '

Neopentyl glycol 12.5

Trail 3.9

This gave a conversion of 87.5% , based on neopentyl glycol, with a selectivity of 50.2% for 1,3-diamino-2,2-dimethyl-propane. Work-up by distillation according to Example 1 gave 392 g of the diamine, corresponding to 57 % of the theoretical amount to be expected from the converted ITopentylglycol.

Example 3

As in Example 1, 312 g of neopentyl glycol and 31 g of a commercially available one were placed in a 10 1-steel autoclave Chromium-nickel catalyst (RCH catalyst 52/35 TS). Then 1,700 g of liquid ammonia were pumped in into the pressure vessel. To activate the contact, another 20 atmospheres of hydrogen were pressed on and then heated Hours at 240 °. After cooling and releasing the pressure in the autoclave, the gas phase is removed and filtered off Catalyst off. The composition of the crude filtrate resulted in the following gas chromatographic analysis:

Product content in percentage of area

Forward 13.1

1,3-diamino-2,2-dimethyl- _{80 6}

propane *

l-amino-3-hydroxy-2,2-dimethyl- η r propane ' *

Neopentyl glycol 1.5

Lag 0.2

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This results in a 98.5% conversion, based on e-phenylglycol. Work-up by distillation by pre-distillation and peel distillation according to Examples and 2 led to 235 g of diamine. This corresponds to a close of 78 % of theory.

The 1-amino-3-hydroxy-2,2-linfibhylpropane obtained during the reaction can - like the unreacted ileopentylglycol - be returned to the process and is also converted into 1,3-diamino-2,2-dimethylpropane during pressure ammonolysis converted, which makes the process particularly economical.

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Claims (4)

- 8 - R 1799 Patent claims Process for the preparation of diamines from dihydric aliphatic alcohols and ammonia in the presence of hydrogen at a temperature of 150 "to 300 ° C and a pressure of at least 10 atm in the presence of a Hickel-containing catalyst, characterized in that for the preparation of l, Bringing 3-diamino-2,2-dimethylpropane neopentyl glycol, ammonia and hydrogen at 220 to 300 ⁰ C with a catalyst which contains 23 to 60 wt.% Nickel deposited on a support material. 2.) The method according to claim 1, characterized in that the temperature is 240 to 260 ⁰ C. 3.) The method according to claim 1, characterized in that Catalysts are used which optionally contain 16 to 40% by weight of chromium. 4.) The method according to claim 1, characterized in that a molar ratio of OH: NH, of 1: 4 bio I: 40 is maintained. 5 ·) The method according to claim 4, characterized in that .that a molar ratio ■
is maintained. a molar ratio of OH: HH, from 1: 6 to 1:20 50S824 /