DE4420360A1 - Conversion of organo-arsenic chemical warfare agent to useful cpds. - Google Patents

Abstract

The process concerns chemical conversion of organo-As chemical warfare agents (I), which are diaryl-halo-arsines, phenarsazine halides, aryl- or alk(en)yl-dichloro-arsines with 1-6 C and cpds. with the pseudo-halogen CN gp. instead of halogen atoms. The process comprises: (a) preparing a soln. S I of (I) in an inert solvent (II); (b) preparing a soln. S II of (II) and Lewis acid or higher fatty acid metal soap as catalyst; (c) mixing an acetylating agent with soln. S II; (d) adding soln. S I to the mixt., giving soln. S III; and (e) working up soln. S III to recover (II) and give ketones and organo-As cpds.

Description

The invention relates to a method for chemical conversion arsenic organic warfare agents.

These warfare agents are or were in the stock of armed men Armed forces or are part of chemical armaments and war veterans most on the mainland and in the seas.

So far, they have been secured and removed by burial, Sinking in water, through temporary storage in landfills and through combustion.

These and other possible methods of destruction and disposal pollute the environment very strongly or make it expensive Arsenic fixations in the gas phase or in the combustion products and required in wastewater. The arsenic products obtained are either not at all or very difficult to work up and therefore only suitable as landfill.

The object of the present invention is therefore a To develop procedures for how environmentally friendly arsenic weapons can be processed and arsenic inorganic substances to be created that can be used chemically and therefore do not need to be deposited.  

This object is solved by the features of claim 1. Advantageous refinements result from the subclaims.

The arsenic-organic warfare agents to be processed are to those from the connecting groups diarylhalosarsine, phenarsazine halides and aryl, alkyl or alkenyl dichloroarsines with C₁-C₆ and those in which the pseudohalogen group instead of halogen atoms Cyan (-CN) is included. Examples are Diphenylchlorarsin, Phenarsazin chloride (also 10-chloro-5,10-dihydrophenarsazine) and phenyldichlorarsine.

The method according to the invention is for arsenic and organic weapons their arsenic organic derivatives, which are liquids, solids or can be in solution, applicable. This applies regardless of yours Origin, state of aging, degree of decomposition and others Nature.

The invention is based on the principle of arsenic organic warfare agents in a liquid phase process ecologically and economically at low Temperatures in reaction products which can be further processed chemically convict. This principle can be implemented; because organic halogen arsenic Compounds are acylatable (MEDINOWSKI in J. Obscei. Khim. Ser. A. 67 (1935) 5.1355) according to the following equations:

PhAsCl₂ + MeCOCl - PHCOMe + AsCl₃

(Ph) ₂AsCl + 2 MeCOCl - 2 PhCOMe + AsCl₃.

Acetyl chloride, acetyl are suitable as acetylating agents according to the invention bromide, propionyl chloride, n-butyl chloride, n-valeryl chloride, benzoyl chloride, acetyl chloride is particularly preferred.  

The invention will now be described in more detail with reference to the figure.

Fig. 1 shows a process scheme for the chemical conversion of organic arsenical agents.

The method according to the invention is used to convert concentrated existing warfare agents, preferably those in storage containers, such as even in ammunition.

It is suitable, the u. U. accumulated or enriched compounds that occur after an extraction or chemical treatment from the decontaminated Material (matrix) were obtained, the inventive method feed and chemically convert.

The solid arsenic-organic warfare agents that are not filled with ammunition, as well as those removed or extracted from ammunition, are crushed in a screw ( 1 ) or a roller crusher in an inert solvent after medium crushing (crushing to a medium degree, on average 5-20 mm in diameter), preferably a halogen alkane or alkene, acetic acid, carbon disulfide or an aromatic solvent, very preferably in 1,2-dichloroethane, trichlorethylene or perchlorethylene, dissolved in a temperature-controlled dissolving kettle ( 2 ). Are there liquid arsenic-organic warfare agents; these are mixed in the dissolving kettle ( 2 ) with stirring and, if necessary, gentle heating with the solvent. At least 1 molar or 20% solution (LI) is prepared and the undissolved portions are removed by filtration or centrifugation ( 4 ).

In a second dissolving kettle ( 3 ), 1.0-3.0 mol, preferably 1.1-2.8 mol, very preferably 1.2-2.4 mol, of catalyst, based on the amount of acetylating agent to be used, are used in the same manner as previously used Solvent dissolved, resulting in solution L II. Lewis acids (Friedel-Crafts catalysts), preferably aluminum (III) chloride and antimony (III) chloride, or metal soaps of higher fatty acids of manganese, nickel and cobalt, such as linoleates, naphthenates, oleates, especially resinates, are suitable as catalysts.

With cooling at reaction temperatures below 40 ° C, preferably 20-38 ° C, particularly preferably 18-35 ° C, at least 1 mole, preferably 1-3 moles, very preferably 1.05-2.2 moles of acetylating agent per mole of arsenic organic The connection is placed in a temperature-controlled stirred tank (= reactor) ( 5 ) and mixed with L II with mechanical or pneumatic liquid circulation.

Thereafter, in the stirred tank ( 5 ) in the temperature range below 35 ° C, preferably 15-35 ° C, very preferably 18-30 ° C, portions of at least 1 mol, preferably 1-2 mol, of the solution LI with circulation of liquid, stirring or inert gas supply ; added (it creates solution L III). The circulation is to be continued for at least 15 minutes, preferably at least 30 minutes, very preferably at least 1 hour, even after the last addition of solution LI.

After several hours, preferably at least 8 hours, very particularly preferably leaving the reaction mixture L in for 12-16 hours it is separated by further processing, e.g. B. distillation; Hydrolysis, separation of the inorganic arsenic compounds and after subsequent distillation; or cooling and subsequent solvent extract tion.  

The most preferred embodiment of the invention is that the chemical conversion of the warfare agents at room temperature into discount continuous operation (batch operation). The ratio of Reactants, arsenic organic compound and acetylating agent, as well The catalyst is preferably approximately stoichiometric to one another. But any other ratio is also possible according to the invention.

Depending on the arsenic-organic weapon to be processed, the Reaction parameters concentration and temperature set to a to achieve optimal conversion accuracy and yield. To the Example are in the reaction of 1 mol of ethyl dichloroarsine with 1.5 Moles of acetyl chloride and 1.6 moles of aluminum trichloride in 1,2-dichloroethane Obtained 0.77 mol of arsenic (III) chloride at 20-23 ° C after 16 hours. At a reaction at 15-18 ° C, 0.68 mol of arsenic (III) chloride are obtained. On the other hand, the conversion of 1 mol of diphenylchloroarsine into 1,2- Dichloroethane at least 2.2 moles of acetyl chloride as an acetylating agent and 2.4 mol of aluminum trichloride as a catalyst and temperatures of 29- 33 ° C. 0.64 mol of arsenic (III) chloride are formed. At lower temp The yield falls with temperatures and less aluminum chloride as a catalyst.

The reaction mixture is separated by distillation, Ab cooling or solvent extraction. The reaction products are: Ketones and arsenic inorganic compounds, preferably arsenic (III) chloride. For example, the reaction of phenylarsine compounds with Ace tyl chloride as ketone acetophenone and as an arsenic inorganic compound Arsenic (III) chloride. This can be done by hydrolysis and other reactions (e.g. oxidation) to other As (III) or As (V) compounds be converted like arsenites and arsenates. After refurbishment the reaction mixture, the solvent is obtained again and the catalyst.  

Up to 80% sales are possible, based on the conversion of organically bound arsenic in arsenic (III) chloride.

Abbreviations used in this application and in FIG. 1 are:
Ac = acetylating agent
AcP = acetophenone
As = arsenic
AsAnV = arsenic inorganic compound
AsOV = arsenic organic compound (weapon)
AsCl₃ = arsenic (III) chloride
Kat = catalyst
Ket = ketones
l = liquid
LI, L II = starting solutions
LM = solvent
+ Q = heat input
- Q = heat dissipation
s = fixed

Claims (5)

1. Process for the chemical conversion of arsenic-organic warfare agents from the compound groups diarylhalogenarsine, phenarsazinhaloge nide, aryl-, alkyl- or alkenyldichlorarsine with C₁-C₆ as well as those compounds which contain the pseudohalogen group-CN instead of halogen atoms, characterized by the following steps:

• (a) preparing a solution LI of the arsenic-organic weapon in an inert solvent,
• (b) preparing a solution L II from inert solvent and catalyst selected from Lewis acids or metal soaps of higher fatty acids,
• (c) mixing an acetylating agent with solution L II,
• (d) supplying solution LI to the mixture from (c) to obtain solution L III,
• (d) Working up the solution L III to recover the solvent used and to obtain ketones and arsenic inorganic compounds.

2. The method according to claim 1, characterized in that as acety letting agent acetyl chloride is used. 3. The method according to claim 1 or 2, characterized in that as Solvent 1,2-dichloroethane, trichlorethylene or perchlorethylene ver is applied.   4. The method according to any one of claims 1 to 3, characterized in net that the reactants and the catalyst in an approximate stoichiometric ratio. 5. The method according to any one of claims 1 to 4, characterized in net that as an arsenic organic weapon Diphenylchlorarsin, Diphe nylcyanarsine, phenarsazine chloride, ethyl dichloroarsine, phenyldichloroarsine or 2-chloroethenyl dichloroarsine is used.