DD200192A5 - METHOD FOR SELECTIVELY SEPARATING CHELATING ISOMERS - Google Patents

Abstract

According to the invention, individual isomers are gradually separated from the mixture of isomers by addition of complexing agents as separation reagents, initially forming a chelate complex with the most strongly binding isomer, this chelate complex, thermally or with chelating agents, such as the disodium salt of ethylenediaminetetraacetic acid, the isomer is liberated and the residual isomer mixture is mixed with further complexing agent, whereby the separation of a next isomer takes place. As separation reagents, transition metal complexes are used which are either coordinatively unsupported or contain labile ligands, e.g. Metal carbonyls, transition metal chelate complexes and / or organometallic compounds.

Description

Title of the invention

Ancestors for the selective separation of chelating isomers

Field of application of the invention:

The invention relates to a process for the selective separation of chelating isomers which can be used in analytical chemistry and in synthetic chemistry.

Characteristic of the known technical solutions:

It is known that the isomer mixtures frequently obtained in chemical coalitions can be separated from one another by customary physical separation processes, such as distillation, fractional crystallization, sublimation, chromatography and variants thereof. However, these methods have limits that result from the chemical nature and embroidered physical constants of the species to be separated. • Separation by distillation is impossible or not useful if the components z. B. form azeotropes or decompose at the Destillationsteiaturatur, have boiling points close to each other or the distillation for economic reasons (too much energy) is not rational. In a similar vein, the other physical separation hypotheses may fail or become uncohenic. In these cases, it is possible to remove certain isomers from the isomeric boric acid with the aid of chemical reactions, preferably from the genic and subsequently to regenerate the isomore from the reaction product. However, this requires that a selective reaction, which proceeds quantitatively and sufficiently quickly, can be found, combined with a similarly rapid and quantitative fiogenation reaction.

ER 1901 * 987139

-A Trennreaktioii iscmeror 1 _P-2 diaminocyclohexanes (dac) was using the Komploxbildung on Zontralmetall nickel (IT) found (R. Saito u. Y. Kidani Chon. Latlers 19? 6, 123). First of all, the diamagnetic planar complex (cis-dac) pIiiCl "is formed. Later, the parauiagnetic octaodrical (trans-dac) ₀ i « ^T iCl _o arises. The pure slide

Cm L *

Mines are to win by a series of other separation and decomposition reaction, in particular, larger amounts of solvents are to evaporate. Despite these necessary operations, this separation process is still more economically advantageous than other methods, especially since it allows products of high purity to be recycled. The principle of separation of isourone divinylbonzenes on cuprous chloride (G. Popov and G. Schvachula, Chem. Techn. J30 (1977) 1) and the separation of butene-1 from the (!) Fraction of industrial petroleum pyrolysis products (R. Schöllner, K. Platzdasch and G. Ulbor Z, Chetn., 17 (1977) 321 and there zit. Lit.) using silver nitrate or auimoniakalischor copper salt solution based on complex binding of oinzühlig acting olefins, which then thermally from the Metallkomploxverbindungen can be separated.

Object of the invention

The object of the present invention is to develop a cheap all-natural process for the selective separation of cholate-forming isomers from isomeric mixtures, which can not be separated by brushless methods, or only incompletely or with a high degree of cost-effectiveness.

Explanation of the essence of the invention

The invention has for its object to ontwiekeln a cheap ancestor for the selective separation cholatbildonder isomeric of isomeric gum isonone, which occur together with other products in technical or prllparativon syntheses.

It has been found that this Ziolstollung is met when separated from the Isomeröngoraisch by adding Komploxbildnorn as separation reagents stufonweiso individual isomers, initially forming a Chelatkomplexos done with the most strongly binding isomerone, diosor "chelate complox due to its poor solubility in nonpolar solvents such as hexane or pentane, thermally or with chelating agents, such as the sodium salt of ethylenediaminetetraacetic acid

233029 3

Isomer is liberated and the isomeric mixture is added to a further complex image, whereby the separation proceeds next in the sonor. The separation reagents used are coordinatively unsaturated complexes having more than one free coordination site or complexes which exchange ligands which are slightly labile and which react with the isomerone in the On the basis of addition or substitution, the reaction to stable nouon Cholatkomploxen react. Moreover, the high separation efficiency is also the case with such isomers, which are different, e.g. positionisomero dialkyl-2,2'-dipyridylo- differ only by the arrangement of the alkyl substituent on the periphery of the molecule.

Trunn reagents according to the invention are:

a) Transitional neutral cholate grain plexo of the general composition

M (LnL) (L * r »L ¹ ) L" where L l and L ^f f% L ¹ are different from each other χ y ζ

or may be the same, L, L 'u. L "are typical coordination atomically active bonding atoms, such as O, K, S, or P darstollon," L "being a monovalent ligand and x, y, ζ stoichiometric factors. Dio-negative chargeon ligands compensate for the positive charge of the overpassion motifs, thus resulting in neutralization complexes. Boispiolo for this double-type having selective release towards chelated isomers: bis-acylacetonatonickel (II) and other β-diketonato-conploxo, bis-pyridine-bis-acetylacetonato cobalt (II), transition metal xanthates, dithiocarbanato or dithiophosphato;

b) metal carbonyls L M (CO), which, apart from CO cleavage with ciolate-forming ·

χ y

Isonieron can react, χ + y is the maximum coordination number of the central emergency II, χ can also assume the jert zero. Examples are: Totracarbonyl-nickol, ilexacarbonyl-molybdenum.

c) Motallorganoverbindungen M (oligoolefin), dio easily oig Oligoolofin abspalton, wherein the chelating end isomer is bound instead. Examples are: bis-cyclooctadione-nickol (O), tris-butadiene-nolybdenum (O).

Suitable chelating isomers are preferably:

Isoaero Dial] Lyl-2,2'-dipyridylc, which, catalytically synthesized from alkyne and nitrites, isomero "1.2 or iodo-1,3-diaraino, such as, for example, 1,2-diamino-cyclohexane, which in conventional synthesis methods in the cis and trans form The isomeric mixture can be used ontv ^ or after removal of solvents, or by-products or directly as a mixture of these components after synthesis has taken place.

Preference is given to boi dor Soaktion with "Übgangsgangscallkomploxon dor thorrao-

22''I'm 3

dynamically stable Ghclaticoiuplox formed, which also nit the highest speed arises. Based on these two fundamentals, the considerable selectivity that achieves up to 100% separation of an isomer. After Cholatkomplexbildung the Cholatkomplex is separated and decomposed due to its Schwor solubility in non-polar solvents such as iloxane or pentane. This clogging can occur either thermally or with other cheap chelating agents that displace the cholating sound. As a cheap Cholatkoraploxbildner z.E. the disodium salt of ethylenediamine-tolacetic acid, which is commercially available and forms water-soluble complexes, so that the eliminated cholatbildondo isomers can be absorbed in non-aqueous, water-immiscible solvent and thus is easy to separate. With Metallkomploxbildung several isomers can be separated stepwise from a Isomerongemisch, when first an isomoros gebundon complex and filled, then by adding weitoron complex a zwoitos isomer is komploxiort etc.

Ausführungsboispiola

example 1

0.2 lilol dor obtained in the karalytischen synthesis of propyne and acetonitrile isomers as Ilauptkonpononten 3 «5-D'imothyl 2.2 ^f ~ dipyridil and 3"6-Dimothyl-2,2'-dipyridil contain, be in ether with 0 1 mol bis-acetylacetonato-nickel (II) goschüttolt, then the solvent is removed, it was added k-0 ml of Iloxan and filtered. In the filtrate remains the isomer 3e6-dimethyl-2 _e 2'-dipyridil, which is not complexed under this Bodingungon. The complex obtained is: 3 »5-3-dimethyl-2,2'-dipyridyl-bis-acetylacotonato-nickel (II), which is practically insoluble in green lime in iloxane and can therefore be used as a precipitate. The decomposition of the complex with the disodium salt of ethylenediaminetetraacetic acid in aqueous-alcoholic solution and shaking out with ether gives an ethereal solution of the pure 3'-5-dimothyl-2,2'-dipyridyl. By distilling off the ether, the pure Isomoro is recovered. Yield: 92 % of the theoretical

Example 2.

An isomeric mixture of 3 "5-dimethyl-2,2'-dipyridyl and 3.6-dimethyl-2,2'-dipyridyl is added in benzene with hexacarbonyl-oxybdenum. Subsequently

It is heated to boiling point until complete evolution of carbon monoxide is calculated for the binding of the ^ i-dimothyl-a, ^ -dipyridyl. Tuft is kept away. The result is a mono-red. dyed solution of 3,5-dimothyl-2.2 ^l dipyridyl-tGtracarbonyl-molybdenum (0), the dio dioxane is concentrated to dryness, and wio is described under 1, worked up. Yield on roinoni isomers 75;

Example 3

The ethoric solution, which after separation of the Comploxes 3 »5-dimethyl-2.2 ⁱ -dipyridyl-bis-acetylacetonato-nickelCll) (see also embodiment and example), will be gelled with 0.1 part of Dis-acetylacetonato-nickol (II) , About 5 hours later, the kouplox 3 "6-ethyl-2,2'-dipyridyl-bis-acetylacotonato-nickel (II) has formed as a pale green compound. Thereafter, the ether is removed by distillation, the residue with uonigon ml. Hexane and filtered "in the filtrate, the byproducts formed during the catalytic synthesis remain. The nickel (H) -IlOnPlOX v / ird, wio under 1 boschriobon, with the dinatriuiasatz of ethylendia; ain-totraossigsn.uro zorsotzt and worked up.

Claims (4)

Erfindungsanspracho: 1. Voi'faliron for scJoktiveii Separation choiatbildondor Isomerer from Isonierongewischon characterized in that from the 1501: 1 engonii sch by the addition of liomplexbildnorn as separation reagent gradually separated individual isomers v / erdon first followed by the formation of a chelate complex don don with the most strongly binding, this cholate cononlox, thermo-odor nit cholating agents, such as the disodium salt of ethyldianiin-tetra-acetic, the Ibomer frog-replaces, and the neston-ammoniated with woiterom complexing agent, whereby the deodorizing of a next iso-orron occurs. 2 method for the soloktivii separation cholate-forming isomers according to item 1 goknnnzeichnot characterized in that as Trennroagcnzion preferably Übergangsraotallkoüiploxe are used which are coordinatively unsaturated or labile bound ligands. 3. Ancestors for the Selective Separation of Chelating Isomers According to Item 1 characterized in that, as transitional ganglion complexes, transitional-chelate complexes of the general co-existence fl (LL) (L ¹ L ¹ ) x · y L "^ inserted v / crdoii, where LL and L ¹ L 'chelate ligand, L" oinzähligo Ligaudcn, L: L ¹ and L "typical liooi'djnationochcuisch v / irksarae Ilaftatome v / io II, 0, S, Γ symbolize on, x, y and ζ are stochiorr.otrischo factoron, which vary within 0-3 limits » 4. Antecedents for the separation by separation chelating donor isomeror according to item 1, characterized in that metal carbonyls of the general composition L ^ I (CO) are used as the boron metal complex, v / oboi L is an open-ended ligand, x + y gives the maximum coordination number of the central mesh used and y between don, ferten 0 and 3 can be varied. 5. Ancestors for seloctive separation chelating isomeror by point 1 characterized in that was used as iibergangsGiotallkoaplexo Ilotallorganovorbindungen dos type M (oligoolofin).