DE694992C - Process for the preparation of lower aliphatic primary oxyalkylamines - Google Patents

Description

Process for the preparation of lower aliphatic.primeren oxyalkylamines The present invention relates to a . improved method of manufacture lower aliphatic primary oxyalkyl arnine, such as i, 3-däaminopropanol-2, i-amino- propanediol - 2; 3, i - aminopropanol - 2 and 2-amino-ethanol i. Primary aliphatic amino alcohol: can be obtained by having the corresponding halogen compound to his excess of aqueous ammonia adds and so. amine halogen salt formed hydrolyzed with caustic alkali to produce the free amine to give birth. This process generates every but always alongside the desired primary changing amounts of secondary and tertiary tertiary amino alcohols by reaction of two or three. Halogen-containing molecules kulen with the same anunoniakmole'kül. One has already tried (cf. American patent i 985 885), the Formation of secondary wind tertiary amino to prevent allkölhol.en by .that one at low temperature and with the 5- to iof the amount for the reaction required amount of ammonia, ac- water worked. Even with one of these Procedure, however, you get a reaction: Qas- mixture, which in addition to primary still 120/0 secondary and tertiary amino alcohol holds so that the actual yield continues primary amino alcohol, related, n -to that chlorohydrin used; nixr .et @ cva 8o% be wearing. According to the present invention it is now possible to eliminate these disadvantages and to obtain practically pure primary anano alcohols in the production of lower aliphatic primary oxyallzylamines by treating the corresponding haloalcohols or haloalkylene oxides with an aqueous ammonia solution. This is achieved by adding the halogen compound to an aqueous ammonia solution which contains more than 25% ammonia, has already been heated to a temperature of at least 45 ° and is under the appropriate pressure. Only after the reaction has ended does it become alkali. added and the ammonia separated by distillation.

It has also been found that in the context of the present proceedings The yield is improved even further if the aqueous ammonia solution is at least 40%, preferably 700b contains ammonia and the aqueous ammonia solution contains ammonium chloride is added. For the quality of the yield, it is ultimately also an advantage when the halogen compound by an indilferent solvent, preferably a lower a11phatic alcohol, is diluted and also this mixture before their Addition to the aqueous ammonia solution heated to temperatures of at least 45 ° will.

The present process is best carried out in a jacketed autoclave which is capable of withstanding the pressure that develops and which is equipped with a stirrer. The aqueous ammonia is introduced into the autoclave and brought to the correct temperature. Halogen alcohol or alkylene oxide is then introduced with stirring and the reaction is allowed to go to the end. The excess ammonia is then drawn off from the autoclave and returned to the collecting container, and the amount of sodium hydroxide corresponding to the halogen present is then added to the mixture. If ammonium chloride is not used, the amount of caustic soda should be equivalent to the halogen originally present in the halogen compound. If ammonium chloride additive was used, an additional amount of caustic soda equivalent to this is required. The amino alcohol formed, after removing the water and alcohol present (if the latter was used as a diluent), conveniently separated from the salts present by distillation at ordinary pressure or under vacuum. Ammonia and alcohol can be fed back into the process. Example i 1,3-D @ iaminopropanol-2 A solution of 375 g of ammonium chloride in 17509 water is introduced into a jacketed autoclave equipped with a mechanical stirrer, 35oog of anhydrous ammonia are added, the stirrer is put into operation and the mixture is thoroughly mixed a suitable heating medium in the jacket heated to 45 to 55 °. A solution of 450: g of glycerol dichlorohydrin in 35 o cc of methyl alcohol is then gradually introduced into the autoclave over a period of 5 minutes.

After 45 minutes, the excess ammonia is drained to the Sanunel container pumped back, the mixture removed from the autoclave and into a .Destillierapparat brought in.

To. Adding 56o g of caustic soda, the released ammonia is distilled off and in: water collected for reuse.

The solution remaining in the still is then concentrated to a small volume. The sodium chloride which separates out is filtered off, the amine is taken up in 500 cc of ethyl alcohol and sodium chloride which precipitates out again is also removed by filtration.

The alcoholic solution is then placed in a vacuum distillation apparatus and the alcohol and residual water are distilled off under normal pressure. The anhydrous amino alcohol is now distilled under a vacuum of approximately 20 mm, boiling point 145 ° to 165 °. The yield of the primary amino alcohol is practically quantitative. EXAMPLE 2 2 i-aminopropanol-2 1n 3000.- Water containing 680 g of ammonium chloride is introduced into an autoclave, 600 g of ammonia gas, the mixture is stirred and heated to 45 ° to 55 °. Then 6509 i-chloropropanol-2 are slowly added. After about 45 minutes of agitation, the excess ammonia is recovered as described above, 80 og caustic soda is added, the sodium chloride formed is separated off and the amino alcohol is dehydrated. It distills under normal pressure at 17o to igo °. The yield of i-aminopropanol-2 is almost quantitative.

Of course, the working conditions just described can be varied within certain limits. As already mentioned, haloalkyl oxides, in particular epichlorohydrin, can also be used as starting materials, since these are known (cf., for example, the aforementioned American patent specification 1 985 885) with ammonia initially to form an amino-halo alcohol and Instead of the chlorine compounds, the corresponding bromine or iodine compounds can also be used;

'It is not necessary in' all cases to post the amino compound Distill removal of the sodium chloride; .da the yield of primary amino alcohol is generally almost quantitative.

Claims (1)

PATENT CLAIMS: i. Process for the production of lower aliphatic primary oxyalkylamines by treating .the corresponding halogen alcohols or -alkylene oxides with an aqueous ammonia solution, characterized in that one the H, aloganver bond is added to an aqueous ammonia solution that contains more than 25% Contains ammonia, is heated to a temperature of at least .45 to 8o ° and is under appropriate pressure after. add alkali to the end of the reaction and that Separating ammonia by distillation. Ä. Method according to claim i, characterized in that that ammonium chloride is added to the ammonia solution. 3. Procedure according to claim i or z, characterized in that the halogen alcohol by a Solvent, preferably a lower aliphatic alcohol, is diluted. q .. The method according to any one of the preceding claims characterized by the Using an ammonia solution; which contains 3o to 7oojo ammonia.