SU482452A1 - Method for preparing imidazolines - Google Patents

Description

one

This invention relates to the field of producing amphoteric surfactants, and specifically to a method for preparing imidazolines. These compounds are used in the textile, metallurgical and mining industries.

A known method for preparing imidazolines from individual fatty acid esters and anhydrous ethylenediamine in the presence of dehydrating agents (in particular, CaO).

The disadvantages of this method are the low yield of imidazolips (35-65%) and the poor solubility of the obtained imidazolips in water.

To increase the yield of the target product and improve its quality, a method has been proposed, according to which a mixture of 75-80% ethylenediamine, 12-15% diethylenetriamine, 6-8% higher amines, and an acid mixture of synthetic fatty acids are used as amines. acids Syu-Ci6 or Ci7-C22. The process is preferably carried out in an organic solvent medium (for example, butanol) at a ratio of acids and amines 1: 3 and a temperature of 120-130 ° C, followed by raising the temperature to 250-270 ° C.

A mixture of amines can be easily obtained by condensation of dichloroethane with 25% aqueous ammonia with a ratio of components of 1: 3, a temperature of 200 ° C, and a pressure of 20 atm for

2 hours €. The subsequent filtration and alkalinization with extraction with butyl alcohol gives a solution of a mixture of amines, which can be used directly for the synthesis of imidizolines. The amine content of the mixture is determined by titration. After carrying out the condensation of fatty acids with amines, the solvent is distilled off and used to re-extract the mixture of amines obtained by reacting dichloroethane with ammonia.

Example I. Obtaining a mixture of amines. In a 2 l autoclave, 312 ml (4 mol) of dichloroethane and 300 ml (12 mol) of 25% aqueous ammonia are charged and heated for 2 hours at 200 ° C and a pressure of 20 at. The precipitate of ammonium chloride is separated, and the excess ammonia is distilled off with steam to form a .100 ml distillation unit.

A reflux condenser is then added and a 40% sodium hydroxide solution is added to the solution to pH 13. The contents of the flask are cooled, filtered, and extracted with butyl alcohol (6 x 150 ml).

The combined extract was dried with granulated caustic liaTpoM, an aliquot (10 ml) was collected and titrated with 1N. PS1 in the presence of methyl red.

The amount of absorbed acid corresponds to the total content of amines in the extract 112 g (48%, in terms of ethylenediamine).

Example 2. Obtaining a mixture of imidazolines.

78 ml of the extract (see Example 1), corresponding to a 0.3 g-eq mixture of amines, and 14.4 g (0.1 gekv) of synthetic fatty acids fraction are introduced into a round-bottomed two-neck flask equipped with a reflux condenser.

The reaction mixture is boiled for 1 hour, after which butyl alcohol is distilled off, and the residue is heated with a Dean-Stark nozzle, a reflux condenser and a thermometer dipped in the reaction mixture to 270 ° C and maintained at this temperature for 1 hour.

The output of the reaction products 16 g (98%, in terms of acid).

When .mmer 3. Getting a mixture of imidazolines.

To 78 ml of an extract of a mixture of amines containing 112 g of amines obtained in the same way as Example 1, 22.5 g (0.1 g-eq) of synthetic fatty acids of the Cue-Cje fraction are added. The reaction mixture is boiled for 1 hour, after which the butyl alcohol is distilled off They are heated and the residue is heated with a Dean-Stark nozzle, a reflux condenser and a thermometer dipped in the reaction mixture to 250 ° C and kept at this temperature for 1 hour.

The yield of reaction products 27 g (97%, in terms of acid). The reaction product has the form of a light yellow paste, solidifying upon cooling.

To prove the structure of the target product in the same way, the individual myristic acid was condensed with ethylene diamine and obtained by the tride cilimidazoline. The product is crystallized from

mixtures of benzene with petroleum ether. Found,%: C 75.7; H 13.0; N 10.9.

CIB ZZ ZCalculated,%: C 76; H 12.8; N 11.2.

Subject invention

Claims (2)

1. A method of producing imidazolines by reacting fatty acids with amines, characterized in that, in order to improve the quality of the final product and its output, the amines use a mixture consisting of 75-80% ethylenediamine, 12-15% diethylenetriamine, 6- 8% higher amines, and as acids a mixture of synthetic fatty acids. 2. A method according to claim 1, characterized in that the reaction is carried out in an organic solvent medium, for example butyl alcohol, at a ratio of acids and amines I: 3 and a temperature of 120-130 ° C, followed by an increase in temperature to 250-270 ° C .