CS200424B1 - Alkylen-n,n'-bis-prolines and process for preparing thereof - Google Patents

Description

It is an object of the present invention to provide novel alkylene-N, N'-bis-proline complexons by condensation, preferably in an alkaline environment, of proline with an alkylenedihalide (preferably ethylenedibromide) wherein the molar ratio of amino acid to alkylenedihalogen is 2: 1 to 5: 1, preferably 2: 1. in 5 6 * 5 or 3: 2a condensation takes place at moderate reflux at a pressure of 10 to 5.10 Pa, preferably 10 *

to 5.10 Pa. Condensation is carried out in an aqueous environment.

The condensation of proline with an alkylene dihalide follows the equation:

200 424

200 424

COOH + XfCHgJjjX

N

H

COOH

+ 2 HX where X = halogen n = 2 to 8

The reaction affords alkylene-R, M'-β-proline and hydrogen halide, which is alkali in the form of the corresponding alkali metal halides, which is favorable for the formation of alkylene-N, N'-b-proline.

and advantageously binds by adding and moving the reaction to the right,

Condensation in an aqueous medium is effected by mixing an aqueous proline solution with an alkylene dihalogenide and an aqueous or aqueous alcoholic / resp. an alkali metal hydroxide solution, but preferably a solid alkali metal carbonate or bicarbonate (or alkaline earth metal) is used. The solution was refluxed with stirring for several hours. After cooling and acidification with an inorganic acid, preferably concentrated hydrochloric acid, the crude alkylene-N, N'-bis-proline is precipitated, which is recrystallized several times from acetic acid and the crystals obtained are dried under vacuum.

An advantage of the preparation of the alkylene-Ν, β-bia-proline according to the invention is that the condensation proceeds sufficiently quickly already under normal pressure and with a significantly higher yield than the processes described for the condensation of lower amino acids.

The novel complexones, alkylene-N, N'-bis-proline, could find use as reagents in analytical chemistry, as new types of catalysts (e.g. for redox processes and the like / and in health as selective detoxifying agents in the treatment of heavy metal poisoning.

Example 1

In a 250 ml three-necked flask equipped with a stirrer, a reflux condenser and a dropping funnel, 20 g (0.5 mol) of Naoh in 38 ml of water was added to 57.5 g (0.5 mol) of L-proline. The solution is heated to boiling and 47 g (0.25 mol) of ethylene dibromide and 34.5 g (0.25 mol) of K2CO3 are added slowly to a pH in the range of 10-11. 10 more hours. After cooling and neutralizing to pH 7 with concentrated hydrochloric acid, a white product precipitates which is recrystallized several times and the acetic acid and the crystals obtained are dried under vacuum. 32 g of ethylene-H, N'-bis-L-proline are obtained in 52% yield. 300 DEG C. (decomposition). Summarized formula ^c , 2 ^ 2 (^ 2 ° 4 * Molel ^{U U} weight 256.3) Elemental analysis: Calculated: C 56.24; N 10.93; H 7.86. Found: 55 78% C; 10.47% N; 7.73% H. The obtained compound was characterized by an IR spectrum which exhibited the characteristic absorption bands of the ethylene-Ν, Ν'-bia-L-proline bonds shown in Table 1. IR spectra were measured on a Perkin Elmer, Model 337, KBr technique.>

200 424

Table 1: Characteristic absorption bands of ethylene-N, N'-bis-L-proline

Pose Position Characteristic Note

3350 - 3500 ^ NH ⁺ valence vibrations 2850 - 2910 ^ CR, valence vibrations 1625 ^ NH ⁺ deformation vibrations 1590 ^ COO " valence vibrations 1460 0¾ acissoring vibration 1415 ^ COO valence vibrations 1300 ^ CR, twist vibration 1260 £ ^ COH deformation vibrations 11Ό0 rocking vibration 1020-1050 ^ C-N valence vibrations 800 ^ c-c valence vibrations

SUBJECT OF THE INVENTION

Claims (3)

SUBJECT OF THE INVENTION 1. Alkylene-M, N'-bis-proline of formula I HOOC COOH O ^{* S * * * *} - ( ^CH 2) _n - ^S O ¹¹ '' where n is an integer from 2 to 8. 2. A process for the preparation of alkylene N, N ' -biaprolines of the formula I, characterized in that in an aqueous or aqueous alcoholic medium proline is condensed with an alkylene dihalogen having 2 to 8 carbon atoms in alkyl, in particular ethylene dibromide, in an alkaline medium. for Reflux and a pressure range of 10 to 5.10 Pa, preferably 1 to 5.10 Pa, in a molar ratio of proline to alkylene dihalogens of 2 to 1: 5, preferably 2 to 1: 3: 2, wherein the product is isolated by acidification with aqueous solution with an inorganic acid, preferably concentrated hydrochloric acid, and purified by recrystallization from acetic acid.