SU765259A1 - Method of preparing complexones of ethylenediamine-n,n'-disuccinic acid or 1,2-diaminocyclohexane-n,n'-disuccinic acid - Google Patents

Description

The invention relates to the production of complexones, derivatives of succinic acid, forming strong complexes with metal ions. Chelators can be used _ for concreteness analytics ^{e-determination} of metal content in natural and synthetic materials, for the analysis and separation of rare earth elements and mixtures thereof.

Known methods for producing complexones - derivatives of both monocarboxylic [1] and dicarboxylic acids [2].

A known method for producing 1,3-diaminopropane-N, N-di-succinic acid 15 as a complexon by the interaction of the sodium salt of aspartic acid with 1,3-dibromopropane in an aqueous alcohol medium by heating and hydrolysis of HB g, and the isolation of the target product 20 in a known manner [h] .

Closest to the proposed is a method for producing complexones - derivatives of succinic acid, 25 in particular, ethylenediamine-Ν, N-di-succinic acid ₍ (EDDJA) and 1,2-diaminocyclohexane-N, N-di-succinic acid (DCDA), which consists in that the corresponding diamine is treated with 30 dipotassium salt of maleic acid in a neutral or slightly alkaline medium in an aqueous solution at 80-90 ° C, followed by treatment with mineral acid to isolate the target product in a known manner [4].

The disadvantage of this method is the low yield of target products. The target product, as a rule, has to be purified from a large excess of inorganic salts and the remainder of unreacted maleic acid. Under synthesis conditions (temperature up to 90 ° С, alkaline ^ medium), the destruction of thermolabile groups is possible.

The purpose of the invention is to obtain more chemically pure chelators derived from succinic acid with a higher yield.

The essence of the invention lies in the fact that to obtain complexones, their tetramyl ’esters are hydrolyzed in an alkaline medium. The synthesis of complexone esters consists in the addition of an alcoholic solution of the corresponding diamine to a cooled ’alcohol mixture of maleic acid diamyl ester. After completion of the reaction at

¹ 5-10 ° C is added diethyl ether, and

- leave in the refrigerator. The precipitated precipitate of the by-product is filtered off, and the filtrate is saturated with dry hydrogen chloride, the precipitated precipitate of complexone tetramyl ether is filtered off, washed with ether and dried. The resulting product is subjected to hydrolysis in an aqueous solution with the addition of solid NaOH at 6070 ° C for two hours. After cooling, it was acidified with hydrochloric acid, the precipitated white precipitate was filtered off, washed with methanol and dried. The product does not require further purification. Obtaining complexones by the proposed method can be illustrated by the following examples. Example 1. Obtaining ethylenediamine-N, N-di-succinic acid (EDDAC). To a mixture of 28.0 g (0.11 mol) of maleic acid diamyl ester and 15 ml of methanol cooled to 5-10 °, a solution of 3.05 g (0.05 mol) of ethylenediamine in 5 ml of methanol is added dropwise with stirring. The reaction mixture is stirred for 4 hours at 5-10 ° C, 25 ml of diethyl ether are added and left overnight in the refrigerator. Precipitated small white wasp: the by-product dock is filtered off and the filtrate is saturated with dry hydrogen chloride. The precipitate of tetramyl ester dihydrochloride EDDIAC was filtered off and washed with ether. Dried at 30-40 ° C. Obtain 29.0 g of dihydrochloride tetraamyl ether EDDYAC. Yield 90%. 25.8 g (0.04 mol) of tetramyl ether-EDDI dihydrochloride are suspended in 100 ml of water, 8.0 g (0.2 mol) of solid NaOH are added and the mixture is heated in a water bath at 60-70 ° C for two hours. After cooling, acidify with concentrated HCl to pH 2.53.0. The fine crystalline white precipitate formed is filtered off, washed with methanol and dried at 8 0-160 ° C. 11.1 g of ethylenediamine-N, N-di-succinic acid are obtained. Yield 95%.

Found,%: C 41.01, H 5.57, N 9.50 ,. “ ^{With N} 2 ° 8 ' ^!

Calculated, Ϊ: C 41.09, H 5.53, 'N9.55.

PRI me R 2. Obtaining 1,2-diaminocyclohexane-N, N-di-succinic acid. (dtsgdyak)

To a mixture of 56, (£ g (0.22 mol) of maleic acid diamyl ester and 30 ml of methanol, cooled to 5-10 ° С, a solution of 11.4 g (0.10 mol) of 1.2- is added dropwise. cyclohexanediamine in 20 ml of methanol The reaction mixture was stirred for 4 hours.

at 5-10 °. Add 80 ml of diethyl ether and leave overnight in the refrigerator. The precipitate of the by-product is filtered off, and the filtrate is saturated with dry hydrogen chloride. The precipitated precipitate of tetraamyl ether dihydrochloride DTSGDYAK is filtered off, washed with ether. Dried at 30-40 ° C. Receive 62.2 g of dihydrochloride tetraamyl ether DTSGDYAK. Yield 89%.

21.0 g (0.03 mol) of DHAEC tetraamyl ether dihydrochloride was suspended in 100 ml of water, 6.0 g (0.15 mol) of NaOH were added and the solution was heated at 60-70 ° for two hours. After cooling, acidify with concentrated HCl to a pH of 2.5-3.0. The precipitate formed is filtered off, washed with methanol and dried at 80-100 ° C. 9.8 g of 1,2-diaminocyclohexane-I, N-di-succinic acid are obtained. Yield 94%.

Found,%: C 48.46, H 6.38, N 8.04, H _2i N ₂ O _g .

Calculated,%: C 48.55, H 6.41, N 8.10.

In this method of producing complexones, derivatives of succinic acid, regardless of the nature of the diamine, the yield of the target products is increased to 83 - 85% (based on the starting diamine); the purity of the synthesized complexones increases due to the absence of unreacted maleic acid and inorganic salts; it becomes possible to avoid the destruction of hermolabile groups and isomeri-. nation due to the mild synthesis conditions.

Claims (1)

Claim A method for producing ethylenediamine-N, N-di-succinic acid or 1,2-diaminocyclohexane-M, N-di-succinic acid complexones based on the corresponding diamine and maleic acid derivative, characterized in that, in order to increase the yield and increase the purity of the target product, the corresponding aliphatic or an alicyclic diamine is reacted with maleic acid diamyl ester in an alcoholic medium at 5-10 ° C., followed by hydrolysis of the resulting complexon tetraester in an alkaline medium.