DE917425C - Process for the production of azomethines - Google Patents

Description

Process for the preparation of azomethines The subject of the invention is a process for the production of azomethines from primary amines on the one hand and from a cyclic radical having an ortho-position hydroxyl group Carbonyl compounds on the other hand, which is characterized in that as primary Amines primary paraffin monoamines are used, which the amino group approximately in in the middle of the carbon chain, preferably those with a total of 9 to 18 Carbon atoms.

The amines proposed for the process according to the invention can have been made in any way, e.g. B. by ketonization of the Fatty acids obtained by paraffin oxidation with subsequent amination by reaction with ammonia and hydrogen. The leeway with regard to the position of the amino group grows as the number of carbon atoms in the paraffin chain increases. Preferably Paraffin monoamines with a total of 9 to 18 carbon atoms are used have because the azomethines produced therewith are particularly easy, for. B. by distillation, clean from admixtures.

Suitable carbonyl compounds include: called 2-oxybenzaldehyde, 2-oxy-3, 5-dichlorobenzaldehyde, 2-oxy-4-methylbenzaldehyde, 2-oxy-5-methylbenzaldehyde, 2-oxy-5-tert-butylbenzaldehyde, 2-oxy-3, 5-dimethylbenzaldehyde, 2-oxy-3, 5-diisobutylbenzaldehyde, 2,6-Dioxybenzaldehyde, 2,4-resorcinol dialdehyde, 2-oxy-i-naphthaldehyde, 2-oxyacetophenone, 2-oxypropiophenone, 2-oxy-5-tert-butyl acetophenone, 2,2'-dioxybenzophenone. Instead of of the listed Carbonyl compounds can also be otherwise substituted Carbonyl compounds are used to carry out the reaction.

The implementation of the carbonyl compounds with those proposed according to the invention Paraffin monoamines are expediently carried out in such a way that approximately molar amounts of the Reaction participants taking into account the heat of reaction occurring with one another brings to action and then the water resulting from the implementation and then the azomethine is distilled in vacuo; any remaining shares of the Starting materials or low-boiling admixtures can be used as intermediate fractions split off. The yields are generally high.

The azomethines prepared according to the invention have a wide variety of uses able to; they can be used in particular as antioxidants and anti-aging agents, especially for oils and fats. Their good solubility is remarkable in mineral oils. This is what distinguishes them advantageously from azomethines, the using other primary amines, such as. B. containing primary amino groups Polyamines or oxyalkyl mono- or polyamines containing primary amino groups, have been manufactured. Apply when using the azomethine in oils and fats it is advisable not to use a chemically pure azomethine, but rather a mixture of azomethines because these often dissolve even better in oils and fats.

In general, from 0.2 to 0.5% of these azomethines, based on this, are sufficient on the oil or fat. Example i In a still equipped with a stirrer become 122 parts by weight of salicylaldehyde within 5 to 10 minutes Stir 228 parts by weight of a paraffin amine containing about 14 carbon atoms contains the amino group in the middle of the carbon chain and at 15 mm boils between 135 and 180 °. The mixture changes color when heated moderately pale yellow and becomes cloudy as a result of the elimination of water. After the addition the entire reaction water, about 18 parts by weight, distilled off and then fractionated the remaining reaction mixture in vacuo distilled. At a vacuum of 15 mm, small portions of one are branched in between 135 and 180 ° passing flow and then gains 326 parts by weight of the formed Orthooxyazomethine as a light yellow oil, which distills between 22o and 246 °. It is easily soluble in hydrocarbons and other organic solvents, such as B. alcohols, acetone, acetic acid esters, chloroform, and corresponds approximately to Composition C21 H350 N. Theory: C = 7g, 430/0; H = 11.16%; N = 4.41 o /,; found: C = 8o, 93 0/0, 81.05%; H = Zr, oo, ii, io 0/0; N = 4.56, 444 To make of the paraffinamine were pre-run fatty acids with a carbon number of 6 to 8 converted into the corresponding ketones in the usual way via their calcium salts, who carry the keto group about in the middle of the carbon chain, then were the ketones in methyl alcoholic solution in the presence of cobalt catalysts 12o ° and a pressure of 12o atm. with excess ammonia and hydrogen be ' acts.

If you add parts by weight of a paraffinic turbine oil to Zoo o,?, "/, of the orthooxyazomethine obtained, so the oil is opposite to oxidizing Largely resistant to influences.

Is used instead of the amine, which contains about 14 carbon atoms one which has about g carbon atoms in the chain and the amino group in whose center carries and which boils at 15 mm between 0 and 13o °, one obtains with otherwise the same working method a light yellow oil with similar properties, which distilled at 15 mm between igg and 21o ° and about the composition Cl0 H25 O N corresponds.

The amine was obtained by ketonization of first run fatty acids with a carbon number of 4 to 5 and subsequent amination in the manner indicated above. Example 2 To 187 parts by weight of 3,5-dichlorosalicylaldehyde with a purity of 90.5% are added within 5 to 10 minutes 158 parts by weight of a mixture of primary paraffinamines, which contains an average of 10 carbon atoms in the chain and the amino group approximately in the middle and which boils at 15 mm between 95 and i35 °; When working according to Example i, 30 parts by weight of an orthoxyazomethine are obtained as a deep yellow oil which distills at 1.5 mm between 180 and 210 ° and, according to the analysis, contains 2450% chlorine and 440.4660% nitrogen. It corresponds to the composition C17 H2 ;, ON C12 with theoretically 21.48% chlorine and 4.24% nitrogen.

In an amount of 0.5% added to a mineral oil, it increases its aging resistance is considerable.

The primary amine used was made by ketonization of initial fatty acids with a carbon number of 4 to 6 and subsequent amination in the example z given way. Example 3 In the same way as described in example i, 172 parts by weight of 2-oxy-i-naphthaldehyde and 171 parts by weight of the paraffinamine mixture are used according to examples around each other; one then receives 308 parts by weight of the corresponding Orthooxyazömethins as a dark yellow oil, which at i to 1.5 mm between i80 and Boils 226 ° and has the composition C21H290N; Theory: C = 8o, 970/0; H = 9.39%, N = 4.50%; found: C = 81.2o, 81.40 0/0; H = 9.50, 9.75 0/0; N = 4.61, 4.85 0/0: The orthooxyazomethine obtained is in hydrocarbons and others organic solvents very easily soluble and has better anti-oxidant Effect on as z. B. disalicylalethylene diimine.

Example 4 Following the procedure of Example i, 237 parts by weight of 5-tert. - Butylsalicylaldehyde with a purity of 75% and 171 parts by weight of the paraffin amine mixture according to example e with one another and thus receives 250 parts by weight of a light yellow oil which is easily soluble in organic solvents and which boils at i mm between 178 and igi °. Example 5 272 parts by weight of 2-oxyacetophenone are combined with 342 parts by weight of paraffin amine according to Example 2 with stirring and first heated on a water bath until most of the water has been split off. The procedure of Example i is continued and 505 parts by weight of orthoxyazomethine are then obtained in the form of a pale yellow oil which is easily soluble in organic solvents and which boils at between 205 and 235 ° at 18 mm.

Claims (1)

PATENT CLAIM: Process for the production of azomethines from primary amines on the one hand and from carbonyl compounds bearing a cyclic radical with an ortho-position hydroxyl group on the other hand, characterized in that primary paraffin monoamines are used as primary amines which carry the amino group approximately in the middle of the carbon chain, preferably those with 9 to 18 total carbon atoms. Cited Papers U.S. Patents Nos. 2,300,998, 2,426,2o6, 2,301,861.