US2215862A - Manufacture of imidazolines - Google Patents

Description

Patented Sept. 24, 1940 PATENT OFFICE aziascz MANUFACTURE OF IMIDAZOLINES Edmund Waldmann, Klolterneuburg, and August Clrwala, Vienna, Germany, assignors, by mesne assignments, to General Aniline a Film Corporation, New York, N. ware Y., a corporation of Dela- No Drawing. Application March 22, 1939, Serial No. scam. in Austria April 4, 1m

This application is a continuation-in-part of application Serial No. 94,120, filed August 3, 1936. This invention relates to the manufacture of imidazollnes containing aliphatic radicals of high molecular weight as substituents at the 2- carbon atom by heating with a fatty acid or a carboxylic acid of high molecular weight to high temperatures, preferably to temperatures lying between 200 and 300 C., a mixture consisting on 1 the one hand of a base having a primary aminogroup and a second primary or secondary aminogroup, which are in 1:2 position to each other, the

two carbon atoms in 1+2-posltion being linked by a single bond, and on. the other hand a salt of such base formed from a strong acid.

Suitable bases having a primary amino-group and a second primary or secondary amino-group in 1:2 position to each other are ethylenediamine'; products such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine; homologues of ethylenediamine such as 1:2-propylenediamine, 2:3-butylenediamine, N-methylethylenediamine.

Suitable strong acids for forming the salts are in particular mineral acids, such as hydrochloric acid, hydrobromic acid, sulfuric acid, and the like.

Suitable fatty acids of high molecular weight are in general aliphatic acids containing more than 8 carbon atoms, for instance caprylic acid, lauric acid, stearic acid, palmitic acid, oleic acid, also mixtures of these acids obtainable by saponifying natural fats like olive oil, tallow, palm oil; also cycloaliphatic acids such as naph- 5 thenic acids and the like.

Instead of the fatty acids there may be used suitable derivatives thereof such as esters, amides, anhydrides or halides; according to the selection of the derivative to be used, the simultaneous use of the free base or the salt of the base may, if desired, be omitted, for in the case of halides the suitable mixtures leading to the desired result are formed, due to the mineral acid becoming free, in the course of the acylation.

Quite generally, the new process consists .in heating with a product selected from the group consisting of fatty acids of high molecular weight 50 and the salts, amides, halides and esters there-;-

of, a mixture consisting on the one hand of a base which is substituted-at two carbon atoms adjacent to each other by an amino-group each, of which amino-groups one contains two hydrogen atoms and the other at least one hydrogen atom, and on the ther hand of a salt of such base with a strong acid, the heating being carried out at a high temperature.

The procedure may also be such that first of all the salt of the mono-acyl compound is prepared. The process then consists in heating to a high temperature a salt formed from a strong acid and such a diamine monoacylated with a fatty acid of high molecular weight, in which the two amino groups are bound to two carbon atoms adjacent to each other, one of which amino groups containing two hydrogen atoms and the other at least one hydrogen atom.

. In the preferred mode of operating, the mixture made in accordance with the invention is heated to a temperature of 250-290 C. If, for example,there is used a quantity of lauric acid, ethylenediamine and ethylenediamine-hydrochloride the hydrochloride which forms a sediment dissolves very quickly in this interval of temperature, even with only gentle stirring, and at the same time causes formation of the undecyl-imidazolinehydrochloride. This reaction may also be conducted at a temperature lower than 250 C. by heating for a longer period. The use of a vacuum during the second half of the condensation is useful.

When the condensation to the imidazoline derivative starts from a mixture of fatty acid amine and aminehydrochloride, the three components of the mixture are advantageously selected so that for 1 mole of the fatty acid or its derivative there are at least 1 mole of the diamine and the salt-like bound mineral acid. In using 1 mole of lauric acid therefore, there should be mole ethylenediamine and /2 mole ethylenediaminehydrochloride, corresponding with the equation CnHaC aminehydrochloride at about 250-290 C. there is obtalned'the reaction in the sense of the following equation:

Cu I ONHOs cNHOOOnHI'I-N Q WQI the product being again undecylimidazoline- 1o hydrochloride in approximately quantitative yield. If, however, the parent material is the monolauroylethylenediaminehydrochloride which already contains in itself per 1 mole fatty acid 1 mole of ethylenediamine and 1 mole of hydrochloric acid, it sumces to heat this hydrochloride by itself to about 250-300 C. in order to obtain an excellent yield'of the hydrochloride of undecylimidazoline. This reaction can also be carried out with the other mono-acyl-derivatives which are obtained from the diamines and the fatty acids of high molecular weight mentioned in paragraphs 2 and 4 of this specification.

Under the effect of the amine salt, particularly the hydrochloride, one finds at comparatively high temperature of reaction evidently an elimination of the acid amide at first formed (as may be seen particularly clearly from the example of dilauroylethylenediamine) and then a combination of the eliminated material directly to the imidazoline hydrochloride. Philipps (Journal of the Chemical Society of London, 1928, page 2393 and following; Chemisches Zentralblatt 1928, vol. 2, page 2466) is of opinion that the formation of benzimidazoles or imldazolines from the acyl-derivatives of the corresponding diamines by boiling with hydrochloric acid occurs of itself in such a manner that the acid amide is first saponified and the eliminated portion united directly to the benzimidazol or imidazoline. These imidazolines of high molecular weight in the form of their salts are freely soluble in water; solutions foam and have good capillary active properties. They may be used with advantage for improving dyeings on vegetable fibers.

Sulfo-groups may be introduced in their molecules by the methods which have become known from French Specification No. 796,917. These imidazoline-sulfonates of high molecular weight 5 are also valuable as wetting, foaming, washing, emulsifying and dispersing agents. They are valuable as assistants in the textile industry.

The following examples illustrate the invention, the parts being by weight:

Example 1 Into a stirring vessel provided with a thermometer and an inverted condenser there are charged 284 parts of stearic acid, 93 parts of ethylenediaminehydrochloride, 56 parts of ethylenediaminehydrate. The mixture is heated while stirring to 120 C. and the temperature is raised 'within 90 minutes to 185 C., whereby between 170 and 185 C. a small proportion of a clear liquid distils (ethylenediaminehydrate and water). The mixture is now heated within 30 minutes to 230 C. and then within 15 minutesto 290 C. The mass is kept for a short time at this temperature, which may be raised to 300 C. until a sample of the mass, tested with water, shows that it is soluble in water to a clear solution; the heating is then interrupted and the mass cooled. The brownish mass, which is crystalline when cold, consists almost exclusively of heptadecyl- .7 imidazolinehydrochloride.

Afreebasemaybeseparatedinknownmanner by dissolving the hydrochloride with water and liberating the base with an alkali-hydroxide which can then be directly filtered. or extracted by means-of benzene. For further. purification 6 the product may be crystallized from a mixture of 3 parts of methyl alcohol and 1 part of water. whereby 2-heptadecylimidazoline is obtained in crystalline scales melting at 94-95" C.

' Example 2 In an apparatus such as is described in Example 1 there is heated a mixture of parts of lauric acid, 40 parts of ethylenediaminehydrate, 60 parts of ethylenediaminehydrochloride in 15 manner described in the same example. As soon as a sample of the mass is clearly soluble in water, the heating is interrupted. On cooling, the mass solidifies in crystalline form; it consists of 2 -undecyllmidazolinehydrochloride. The base 2 liberated in the usual manner from this salt may be purified by recrystallization from alcohol of 50 per cent. strength, whereby it is obtained in the form of colorless laminae which melt at 82 C.

Example 3 26 In an apparatus such as is described in Example 1 there is heated to 180 C. a mixture of parts of oleic acid, 15 parts of ethylenediaminehydrate; the mass which at first is somewhat 30 foamy boils finally gently as soon as the water has been distilled. After cooling to 120 0. there are added another 15 parts of ethylenediaminehydrate and heating is renewed to C. 37.5 parts of ethylenediaminehydrochloride are now 35 added, whereupon the temperature of the mass is raised to 280 C. within 15 minutes and kept there for 10 minutes. The mass is then allowed to cool to 120 C., another 10 parts'of ethylenediaminehydrate are added, and the mixture is 40 heated within 20 minutes to about 300 C. and kept at this temperature until a sample dissolves clearly in water, whereupon the heating is immediately interrupted.

In this manner there is obtained the 2-hepta- 5 decenylimidazolinehydrochloride in the form ofv a semi-solid brownish mass which dissolves clearly in water with the formation of a strongly foaming solution from which the base may be isolated in the usual manner. 50

Example 4 I Ezram le 5 8.5 parts of N-N-Di-lauroylethylenediamide are heated with 3.3 parts of ethylenediaminehydrochloride in an open flask, while stirring, in such a manner that after 5-10 minutes the mixture has a temperature of about 270-280 C. The 70 heating is continued for another 10 minutes to 280-290 C., whereby the greater quantity of the hydrochloride passes into solution. A sample then dissolves clearly in water.

Caustic soda solution precipitates from the' aqueous solution the undecylimidazoline which is the product of reaction in approximately quan-. titative yield.

Example 6 55 parts of stearic anhydride, 9.5 parts of ethyl- ;nediaminehydrate and 14.4 parts of ethylenediamlnehydrochloride are condensed in the usual manner as described in Example 1' so as to form the heptadecylimidazolinehydrochloride. A whitish-yellow melt is obtained which forms with water a clear, strongly foaming dispersion.

Ezamle 8 A mixture of 9 grams of ethylenediaminehydrate and 44 grams of myristic anhydride is gradually heated, while stirring, to 110 C. to 130 C. 8 grams of ethyienediaminedlhydrochloride are added to the clear melt and the reaction mass is further heated to 280 C. to 290 C. until;

the melt dissolves clearly in water.

The tridecane A2 imidazolinehydrochloride thus obtained is a light brown mass which readily dissolves in water with formation of foam and may readily be transformed into the base by means of alkalies.

We claim:

1. Process for the manufacture of 2-substituted imidazolines which comprises reacting one mol of a product selected from the group consisting of the fatty acid anhydrides and naphthenic acid anhydrides with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature.

2. Process for the manufacture of 2-substituted imidazolines which comprises reacting one mol of a product selected from the group consisting of the fatty acid anhydrides and naphthenic acid anhydrides with half 8. mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature while using an excess of the free base.

3. Process for the manufacture of 2-substituted imidazolines which comprises reacting one mol of a product selected from the group consisting of the fatty acid anhydrides and naphthenic acid anhydrides with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature while using an excess of the salt of the base with a strong acid.

4. Process for the manufacture of 2-substituted imidazolines which comprises reacting one mol of a product selected from the group consisting of the fatty acid anhydrides and naphthenic acid anhydrides with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being carried out at a high temperature while using an excess of the free base and the salt of the base with a strong acid.

5. Process for the manufacture of 2-substltuted imidazolines which comprises reacting one mol of a product selected from the group consisting of the fatty acid anhydrides and naphthenic acid anhydrides with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linked by a single bond by an amino group each, of which amino groups one contains two hydrogenatoms and the other at least one hydrogen atom, and with half a. mol of a salt of such a base with a strong acid, the reaction being carried out at temperatures lying between 200 C. and 300 C.

6. Process for the manufacture of 2-substituted imidazolines which comprises reacting one mol of a product selected from the group consisting of the anhydrides of the fatty acids containing 10 to 18 carbon atoms with half a mol of a base which is substituted at two carbon atoms adjacent to each other and linkedgby a single bond by an amino group each, of which amino groups one contains two hydrogen atoms and the other at,

least one hydrogen atom, and with half a mol of a salt of such a base with a strong acid, the reaction being otherwise carried out at a high temperature. I

7. Process for the manufacture of 2-substituted imidaaolines which comprises reacting one mol of a product selected from the group consisting of the anhydrides of the fatty acids containing 10 to 18 carbon atoms with half 9. molof ethylene diamine and half a mol of a salt of ethylene diamine with a strong acid, the reaction being carried out at temperatures lying between 200 C. and 300 C.

8. Process for the manufacture of 2-substituted imidazolines which comprises reacting one mol of a product selected from the group consisting of the anhydrides of the fatty acids containing 10 to 18 carbon atoms with half a tool of ethylene nnmmn wannmmz. .wcus'r CHWALA.