Phenyl dichloroarsine

Phenyl dichloroarsine was prepared in 1878 by La Coste and Michaelis by passing the vapours of benzene and arsenic trichloride through a heated tube. The product obtained was impure with the diphenyl compound and could be purified by distillation or crystallisation only with some difficulty. The same workers later studied another method for its preparation. This is more convenient and consists in heating mercury diphenyl to 250° C. with an excess of arsenic trichloride. 

Phenyl dichloroarsine may also be obtained by heating triphenylarsine with arsenic trichloride in a closed tube to 250° C. for 30 hours  

Roeder and Blast s method, mentioned above, is usually employed for the preparation. 50 gm. mercuric acetate are dissolved in 50 ml. acetic acid in a thick-walled flask. 100 ml. benzene, free from thiophene, are added and the mixture heated 

Phenyl dichloroarsine when pure is a colourless liquid which gradually turns yellow. At ordinary pressures it boils at 255° to 257° C. and at 14 mm. pressure at 124° C. At — 20° C. it solidifies to a microcrystalline mass. The specific gravity is 1-654 20° C. 

Its vapour tension at temperature t may be calculated from the formula  

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Phenyl Carbylamine Chloride Phenyl Dibromoarsine Phenyl Dichloroarsine Phenyl Mercury Acetate Phenylaceyl Chloride Phenylarsenic Dichloride Phenylarsonous Dichloride Phenylcarbamine Phenylcarbonimidic Dichloride Phenylchloromethylketone Phenylisocyanide Dichloride Phenylisonitrile Dichloride Phenylmethylaminpropane Philippine Downy Mildew Phix... 

The phenylarsenous oxide solution is most conveniently prepared from phenyl-dichloroarsine, which is readily available from phenylarsonic acid. Crude phenylarsonic aoid (404 g., 2 moles) is dissolved in concentrated hydrochlorio aoid (700 cc.) and treated with a stream of sulfur dioxide. From time to time a trace of potassium iodide solution is added (0.2-0.5 g. of potassium iodide is usually sufficient to complete the reduction). When the hydrochloric acid solution becomes clear and the addition of more potassium iodide does not form a permanent cloudiness the reaction is complete. Two to three hours is usually required for this reaction. The crude phenyldichloroarsine separates as a heavy oil. The oil is removed, dried with calcium chloride, and fractionally distilled at reduced pressure in a stream of carbon dioxide or nitrogen. The nearly colorless product boiling at 140-143°/40 mm. is collected it weighs 334-400 g. (75-90%), depending on the purity of the original phenylarsonic acid. 

SYNS 2-AMINO-4-DICHLOROARSINOPHENOL HYDROCHLORIDE (3-AMINO-4-HYDROXYPHEN-YL)ARSONOUS DICHLORIDE MONOHYDROCHLORIDE 3-AMINO-4-HYDROXYPHENYL DICHLORARS-INE HYDROCHLORIDE (3-AMINO-4-HYDROXY-PHENYL)DICHLOROARSINE HYDROCHLORIDE ARSECLOR CHLORARSOL CHLORASEN CLORARSEN DICHLOROMAPHARSEN FILARSEN FONTARSOL HALARSOL R.P. 2591... 

In the series of aromatic arsines there is a great difference in aggressive action between triphenyl arsine, phenyl dichloroarsine and diphenyl chloroarsine. 

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

Phenyl /3 chlorovinyl chloroarsine (b.p. 140° to 150° C. at 10 mm. mercury pressure) was obtained by the reaction of acetylene with phenyl dichloroarsine in the presence of aluminium chloride ... 

Water. Phenyl dichloroarsine on treatment with water is hydrolysed to phenyl arsenious oxide ... 

Alkali Hydroxides. Phenyl dichloroarsine is also hydrolysed by the action of alkali hydroxide solutions. The phenyl arsenious oxide in presence of excess alkali is converted to the salt of the corresponding phenyl arsenious acid ... 

Halogens. With chlorine and phenyl dichloroarsine, an additive compound is formed, tetrachloro phenylarsine. This decomposes into phenyl arsenic acid in the presence of moisture. 

Bromine, however, forms no additive compound. By treatment of phenyl dichloroarsine with excess of bromine, the molecule is decomposed with formation of dibromobenzene, arsenic chloro-bromide and hydrobromic acid, as follows ... 

Ammonia. By the action of gaseous bromine on phenyl dichloroarsine in benzene solution, phenyl arsenimide is obtained ... 

Amines. Primary and secondary amines, both of the aliphatic and aromatic series, react vigorously with phenyl dichloroarsine, giving compounds of the following types ... 

Hydrogen Sulphide. By the action of hydrogen sulphide on phenyl dichloroarsine in alcoholic solution, phenyl arsenious sulphide, CgHjAsS, is produced in crystals melting at 152° C., or 174° to 176° C. This reaction is very sensitive, and as the sulphide obtained is insoluble in water, its formation may be employed to detect small quantities of the arsine (0-05 mgm. in I ml. water). 

Silver Cyanide. By prolonged boiling (5 hours) of silver cyanide with phenyl dichloroarsine in benzene solution, phenyl dicyanoarsine, CgHsAs(CN)2, is formed as crystals with an odour which is both aromatic and also resembles hydrocyanic acid. It melts at 78-5° to 79-5° C., and is readily decomposed by water or even by damp air, with formation of phenyl arsenious oxide and hydrocyanic acid. 

Acid Chlorides. Phenyl dichloroarsine, when treated with the aliphatic acid chlorides, e.g., acetyl chloride, in carbon disulphide solution and in presence of aluminium chloride, forms acetophenone and arsenic trichloride ... 

Diphenyl Arsine. By the action of diphenyl arsine on phenyl dichloroarsine, arsenobenzene and diphenyl chloroarsine are formed ... 

Pure phenyl dichloroarsine does not attack iron. 

Phenyl dichloroarsine was employed during the war of 1914-18 first by the Germans as a solvent for diphenyl cyanoarsine and later by the French in admixture with 40% of diphenyl chloroarsine under the name of Sternite. ... 

Phenyl dichloroarsine is a lung irritant, a vesicant and a lachr5miatory. The maximum concentration which a normal man can support for not more than a minute is 16 mgm. per cu. m. of air (Flury). The mortality-product is 2,600 for 10 minutes exposure (Prentiss). 

Diphenyl chloroarsine was prepared in 1880 by La Coste and Michaehs by heating mercury diphenyl with phenyl dichloroarsine ... 

By the reaction between phenyl dichloroarsine and diphenyl arsine ... 

First fraction, 150° to 190° C., consists of a mixture of phenyl dichloroarsine and diphenyl chloroarsine. 

The residue consists chiefly of triphenyl arsine, which is extracted with chloroform and treated, after evaporating off the solvent, with phenyl dichloroarsine in an autoclave. About 60% of diphenyl chloroarsine is thus obtained. 

The English and French, employing the method of Michaelis, modified by Pope and Turner, succeeded in obtaining a mixture containing 60-65% diphenyl chloroarsine and 35-40% phenyl dichloroarsine, which was employed without further treatment. 

It is only slightly soluble in water, 100 ml. dissolving less than 0 2 gm. However, it is readily soluble in carbon tetrachloride, phosgene, chloropicrin and phenyl dichloroarsine. In other solvents it dissolves in the following proportions ... 

Determination of Phenyl Dichloroarsine Fleury s method may be employed for this determination it consists in hydrolysing the sample with water and titrating the oxide formed with iodine solution. The following reaction takes place ... 

A sample of phenyl dichloroarsine is weighed accurately, treated with water and alcohol and then titrated, without adding any sodium bicarbonate, with a decinormal solution of iodine, until the yellow colour is permanent. The number of ml. of iodine solution employed multiplied by o>oiii5 gives the amount of phenyl dichloroarsine (in gm.) in the sample. 

Fleury recommends the following method for the determination of the arsenic chloride present in a sample of phenyl dichloroarsine. 

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