Methyl dichloroarsine

MD Mercury azide Mercury fulminate Mercury fulminate Mercury nitride Methylene dinitramine Methyl dichloroarsine... 

Auxotoxic Group. Methyl, ethyl, vinyl, phenyl. Includes Methyl dichloroarsine. . CHgAsCL... 

I CCIsNOj Chloropicrin /CHaCl CHaCl Dichloromethyl ether COClj Phosgene < Cl—COOCCls Diphosgene >< CHj—AsClj Methyl dichloroarsine... 

Methyl dichloroarsine. Ethyl dichloroarsine. Chlorovinyl arsines. Phenyl dichloroarsine. Diphenyl chloroarsine. Diphenyl cyanoarsine. 

Of the ahphatic arsines, only ethyl dichloroarsine has been widely employed as a war gas and is considered as the typical substance for use in projectiles. Methyl dichloroarsine is classed by some German authors as a substance which was studied in the post-war period, but according to an American authority it was actually employed by the Allies towards the end of the war, though only in small quantity. ... 

For instance, dimethyl chloroarsine (b.p. 106 5° to 107° C.), dimethyl bromoarsine (b.p. 128° to 129° C.), dimethyl fluoro-arsine, methyl dicyanoarsine (m.p. 115 5° to ii6 5°C.), ethyl dibromoarsine, etc. All of these have aggressive properties inferior to those of methyl dichloroarsine. 

Homologues of methyl dichloroarsine have also been prepared n-Butyl-dichloroar sine, C4H9ASCI2, obtained by the action of hydrochloric acid on -butyl arsenic acid in the presence of sulphur dioxide, is an oily liquid boiling at 192° to 194° C. 

Methyl dichloroarsine was prepared by Bayer in 1858 by two different methods ... 

Methyl dichloroarsine may also be obtained by treating dimethyl arsine with chlorine ... 

It is easily understood that this reaction, though convenient enough for the laboratory preparation of methyl dichloroarsine, is not suitable for its industrial manufacture because of the difficulty of procuring large quantities of the raw materials. The lack of an easy and simple method of manufacture may be considered as one of the principal causes which prevented methyl dichloroarsine from being employed as a war gas until the very end of the war, when only the Americans succeeded in producing it on an industrial scale by a simple method. 

In the laboratory, methyl dichloroarsine may be prepared by the method indicated above. ... 

When all the dimethyl sulphate has been added, the flask is fitted with a reflux condenser and the contents boiled for 2 hours. The sodium salt of methyl arsenic acid is obtained. It is allowed to cool and a small amount of potassium iodide is added, after which a current of sulphur dioxide is passed through the liquid until it is saturated (about 6 hours). The mixture is again boiled under reflux for about an hour during this period, an oily substance consisting of methyl arsenious oxide deposits at the bottom of the flask, where it is saturated with a current of gaseous hydrochloric acid, while the flask is cooled externally. On attaining complete saturation, the flask is connected with a Liebig s condenser and the liquid distilled. Much hydrochloric acid is evolved at first later a mixture of hydrochloric acid and methyl dichloroarsine distils over. The distillation is continued until no more oily liquid condenses. The distillate is placed in a separatory funnel and the oily layer separated and distilled. 

A diagram of the American plant for the manufacture of methyl dichloroarsine is shown as Fig. 15. 

The distillate is collected in a separatory vessel, and the oily layer dried with calcium chloride and fractionally distilled from an oil-bath. The methyl dichloroarsine passes over between 129° and 133° C. 

Methyl dichloroarsine is a mobile, colourless liquid which has a characteristic odour and does not fume in the air. 

In contact with alkaline solutions, methyl dichloroarsine is quantitatively decomposed ... 

Solutions of methyl dichloroarsine in carbon disulphide when cooled to — 10° C., easily absorb chlorine forming large crystals of methyl tetrachloroarsine, which decompose at 0° C. into methyl chloride and arsenic trichloride ... 

Methyl dichloroarsine reacts with bromine water, forming methyl arsenic acid ... 

Methyl arsenic acid forms acicules with a melting point of 159° C. It is also obtained by the action of hydrogen peroxide on methyl dichloroarsine. ... 

In dry ether solution, methyl dichloroarsine does not react with magnesium, though in presence of water the reaction is violent methyl arsine, hydrogen, methane and a compound, (CH3As),j, are formed. Zinc reacts similarly. ... 

Aqueous solutions of methyl dichloroarsine reduce ammoniacal silver nitrate solutions (Nametkin). 

Methyl dichloroarsine reacts with acetylene in presence of anhydrous aluminium chloride, forming a mixture of ... 

This is a liquid with a boiling point of 112° to 115° C. at 10 mm. mercury pressure, which behaves chemically in a similar manner to methyl dichloroarsine. It has a lesser irritant power, but has a vesicant action on the skin, producing blisters which are difficult to heal. 

Dry methyl dichloroarsine does not attack iron or zinc (Prentiss). 

In the laboratory, ethyl dichloroarsine may be obtained by the action of ethyl iodide on sodium arsenite by a method similar to that described already for the preparation of methyl dichloroarsine ... 

American Method. In America, a similar method was employed for the manufacture of ethyl dichloroarsine to that already described for methyl dichloroarsine. It consisted essentially in treating sodium arsenite with diethyl sulphate, then with diethyl sulphate, reducing the product obtained with sulphur dioxide and then chlorinating with hydrochloric acid. 

The volatility of ethyl dichloroarsine is lower than that of methyl dichloroarsine (Herbst) ... 

The velocity of the hydrolysis is approximately equal to that of methyl dichloroarsine. The ethyl arsenious oxide which forms is a colourless oil, with a nauseating, garlic-like odour, but without vesicant action, which rapidly oxidises in the air to form colourless crystals. Its specific gravity is i-8o2 at 11° C., it boils at 158° C, at 10 mm. mercury pressure and is soluble in benzene, ether and acetone. 

This substance, like methyl dichloroarsine, has a vesicant action on the skin, which, according to Strughold, is perceptible at a concentration of i mgm. per sq. cm. of skin. 

P Chlorovinyl methyl chloroarsine (b.p. 112° to 115° C. at 10 mm. mercury pressure) was obtained by Das Gupta, by the action of acetylene on methyl dichloroarsine (see p. 278) in the presence of anhydrous aluminium chloride ... 

Detection of Methyl Dichloroarsine On adding a few drops of an aqueous solution of mercurous nitrate, faintly acid with nitric acid, to a solution containing methyl dichloroarsine, a grey precipitate of metallic mercury is formed. 

Determination of Methyl Dichloroarsine For this determination, the following method has been recommended by Uehlinger and Cook ... 

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