CS268204B1 - Method of 2-aluminium propanolate's and amine's or amonia's trimes's complex preparation - Google Patents

Abstract

The solution relates to a method of preparation binding complex compounds of trimer of aluminum 2-propanolate with ammonia or primary or secondary amine. The complex compound formed serves as an effective catalyst in preparation carboxylic acid amides by aminolysis esters of these acids.

Description

The invention relates to a process for the preparation of a complex compound of general formula I

R

wherein R represents a group of atoms (CH 2, CH-, R 2 represents a hydrogen atom or an alkyl having 1 to 4 carbon atoms and R 4 represents the same as R ₁ or phenyl, benzyl, dimethylaminoalkyl and 1 to 4 carbon atoms or diethylaminoalkyl having 1 to 4 carbon atoms; up to 4 carbon atoms formed by coupling an aluminum 2-propanolate trimer with ammonia or an amine of formula II

II.

in which R ₁ and R 2 denote the same as in formula I.

The complex compounds of the formula I can expediently be used as effective catalysts for certain chemical reactions, in particular for the preparation of carboxylic acid amides by aminolysis of esters of these acids.

The complex compounds of formula I were not known. The existence of complex compounds of general formula I was found in an experimental study of the preparation of carboxylic acid amides by aminolysis of esters of these acids by the action of an amine in the presence of aluminum 2-propanolate.

This experimental study was based on the known fact that aluminum 2-propanolate exists in two polymeric forms depending on the temperature and the duration at this temperature. At temperatures below 40 ° C the stable form of polymerization of aluminum 2-propanolate is tetramer, at temperatures above 40 ° C the stable form of polymerization of aluminum 2-propanolate is trimer. The change of the aluminum 2-propanolate trimer in the tetramer and vice versa is reversible and dependent on temperature changes Γ V. 3. Shiner et al .: J. Am. Chem. Soc. 85, 2318 (1963)] · ^L

For the experimental study of the effect of aluminum 2-propanolate on the course of aminolysis of carboxylic acid esters, an aluminum 2-propanolate tetramer was prepared daily

CS 268204 B1 by standing distilled aluminum 2-propanolate. The conversion of aluminum 2-propanolate trimer to tetramer was monitored using NMR spectral analysis. It has been found that the conversion of the aluminum 2-propanolate trimer to the tetramer is accompanied by cleavage of the NMR spectrum of the trimer. After eight days, the trimer of 2-propanolate is completely converted to the tetramer, which is a crystalline structure, and at the same time the NMR spectrum of the trimer is completely cleaved. Aluminum 2-propanolate trimer was prepared by heating the tetramer of this compound at 110 ° C for six hours.

In this experimental study, it was found that aluminum 2-propanolate tetramer has no effect on the mixture of carboxylic acid ester and ammonia or amine. Furthermore, it has been found that aluminum trimer of 2-propanolate on contact with ammonia or an amine of formula II immediately gives a complex compound of formula I by reacting equivalent amounts of reactants, i.e. 1 mol of aluminum 2-propanolate trimer and 1 mol of ammonia or amine of formula II. II. The reaction is accompanied by the release of heat and the immediate resolution of the NMR spectrum of the aluminum 2-propanolate trimer to a spectrum very closely similar to that of the tetramer of this compound. The discovered complex compounds of general formula I are insoluble in alkanes as well as in lower alkanols, such as methanol, ethanol, 2-propanol, sparingly soluble in toluene, chloroform, trichlorethylene, they are well soluble in amines of general formula II.

The melting points of these complex compounds are surprisingly high, exceeding 118 ° C, which is the beginning of the melting point of the complex formed by the coupling of aluminum 2-propanolate trimer and ammonia.

The complex compounds of formula I are stable even at temperatures up to 190 ° C, i.e. at temperatures which exceed their melting points.

The use of the discovered ability of the aluminum 2-propanolate trimer to provide a complex compound of formula I by reaction with β with ammonia or an amine of formula II is an object of the present invention.

The essence of the process for the preparation of the complex compound of general formula I according to the invention is that this compound is formed by reacting aluminum 2-propanolate trimer with ammonia or amine of general formula II as a result of mixing these reactants at temperatures up to 48 ° C. .

As the reaction medium for the process for preparing the complex compound of the general formula (I) of the present invention, an amine of the general formula (II) or an alkane of β 6 to 12 carbons or an aromatic hydrocarbon such as toluene, xylenes and the like are used.

The process for the preparation of the complex compound of the general formula (I) according to the invention is shown in the working examples, but is not limited thereto.

Example 1

To a stirred solution of 183.6 g (0.3 mol) of aluminum 2-propanolate trimer in 600 ml of n-hexane in a 2.5 L flask with stirrer, thermometer and descending condenser at 20 ° C was added 10.2 g (0.6 mol) of liquid ammonia. Unreacted ammonia was separated from the resulting crystalline substance by distillation together with n-hexane under reduced pressure to 18 kPa. The crystalline substance was separated by filtration. 177 g (0.28 mol) of the complex compound formed by coupling aluminum trimer of 2-propanolate with ammonia were obtained. The melting point of this substance is 118 to 127 ° C.

Example 2

To a solution of 183.6 g (0.3 mol) of aluminum 2-propanolate trimer in 600 ml of n-hexane, placed in the apparatus as in Example 1, was added 19.5 g (0.33 g) at 20 ° C with stirring and cooling with water. mol) 2-propylamine. The temperature of the reaction mixture rose to 28 ° C. The resulting crystalline substance was separated by filtration. 195 g (0.29 mol) of a complex of CS 268204 B1 3 compounds formed by coupling aluminum trimer of 2-propanolate β with 2-propylamine were obtained. The melting point of this substance is 127-136 ° C.

Example 3

To a solution of 83.6 g (0.3 mol) of aluminum 2-propanolate trimer in 600 ml of toluene, placed in the apparatus as in Example 1, was added 22 g (0.3 mol) of diethylamine at 20 DEG C. with stirring and cooling with water. The temperature of the reaction mixture rose to 29 ° C. The resulting crystalline substance was separated by filtration. 165 g (0.24 mol) of the complex compound formed by coupling of aluminum 2-propanolate trimer with diethylamine were obtained. The melting point of this substance is 128 to 136 ° C.

Example 4

To a solution of 183.6 g (0.3 mol) of aluminum 2-propanolate trimer in 600 ml of n-hexane, placed in the apparatus as in Example 1, 35 g (0.3 mol) was added at 20 ° C with stirring and cooling with water. ) diethylaminoethylamine. The temperature of the reaction mixture rose to 29 ° C. The resulting crystalline substance was collected by filtration. 212 g (0.29 mol) of the complex compound formed by coupling of aluminum 2-propanolate trimer with diethylaminoethyl amine were obtained. The melting point of this substance is 123 to 130 ° C.

Example 5

To 290 g (2.4 mol) of diethylaminoethylamine placed in the apparatus as in Example 1 was added 193.6 g (0.3 mol) of aluminum 2-propanolate trimer at 20 ° C with stirring and cooling with water. The temperature of the reaction mixture rose to 32 ° C. The resulting solution contained 218.4 (0.3 mol) of complex compounds formed by coupling aluminum aluminum 2-propanolate trimer with diethylaminoethylamine.

Claims (1)

OBJECT OF THE INVENTION Process for the preparation of a complex compound of general formula I In which R denotes a group of atoms (CH 2 JCHCH, R ₁ denotes a hydrogen atom or an alkyl and 1 to 4 carbon atoms and R g denotes the same as R ₁ or phenyl, benzyl, dimethylaminoalkyl and 1 to 4 carbon atoms or diethylaminoalkyl and 1 up to 4 carbon atoms, characterized in that ae is reacted with an aluminum 2-propanolate trimer and ammonia or an amine of general formula II II »wherein R ₁ and R 8 are as defined above, with an excess of amine ob. vz. II, or in an alkane having 1 to 12 carbon atoms or in an aromatic hydrocarbon and 6 to 9 carbon atoms at a temperature up to 4c ° C.