Diiodoethyl sulphide

The monosubstituted derivatives, ethyl ]8 chloroethyl sulphide and ethyl ]8 bromoethyl sulphide, are weak in toxicity, as is also the disubstituted compound aa dichloroethyl sulphide. The disubstituted derivative with both the halogen atoms in the )8 position, jSjS dichloroethyl sulphide, however, is powerfully toxic and vesicant it is more commonly known as " Mustard Gas" Other derivatives analogous to /SjS dichloroethyl sulphide have been prepared, such as /S/3 dibromoethyl sulphide and /3/S diiodoethyl sulphide, which have similar physiopathological properties, as well as homologues of /3/S dichloroethyl sulphide such as /3/3 dichloropropyl sulphide (I) and /3/3 dichlorobutyl sulphide (II) ... 

With Hydriodic Acid. By the action of hydriodic acid in aqueous or acetic acid solution on dichloroethyl sulphide, both the chlorine atoms are substituted by iodine atoms and diiodoethyl sulphide is obtained (see p. 244). 

Divinyl sulphide is also formed by the abstraction of two molecules of water from one of thiodiglycol. On treatment with gaseous hydrochloric acid, it forms aa dichloroethyl sulphide, a colourless liquid with a penetrating odour, which boils at 58 5° C. at 15 mm. mercury and has a density of 1-1972 at 15° C. On treatment of divinyl sulphide in aqueous solution with hydriodic acid, 8/3 diiodoethyl sulphide is formed (see p. 244). With chlorine various chlorinated compounds are formed, for instance, a/3 dichloroethyl vinyl sulphide ... 

Diiodoethyl sulphide is prepared according to Grignard by treating dichloroethyl sulphide with sodium iodide in acetic acid solution and heating to 60° C. On pouring the product into water, a crystalline product is obtained and this is then purified by recrystallisation. 

Diiodoethyl sulphide forms bright yellow prisms melting at 62° C. according to Grignard, and at 68° to 70° C. according to Kretov. ... 

Diiodoethyl sulphide reacts with methyl iodide more readily than the dichloro- compound to form dithiane methiodide ... 

Diiodoethyl sulphide has a vesicant action on the skin similar to that of dichloroethyl sulphide (Helfrich). 

The dichloroethyl sulphide is converted to diiodoethyl sulphide which separates as yellow crystals. 

The copper sulphate is added in order to catalyse the reaction, while the gum arabic causes the diiodoethyl sulphide to separate in the colloidal form instead of crystalline. 

For the detection of dichloroethyl sulphide, the air under examination is passed through the reagent prepared as described above. In the presence of dichloroethyl sulphide a yellow precipitate of diiodoethyl sulphide separates. According to Grignard, 100 mgm. dichloroethyl sulphide may be detected in I cu. m. of air in 4 minutes. 

The Method of Grignard, Rival and Schaichard This method is based on the conversion of dichloroethyl sulphide to diiodoethyl sulphide by means of hydriodic acid in acetic acid solution ... 

The flask is shaken to dissolve the diiodoethyl sulphide, the contents diluted to volume and shaken again to homogenise the solution. After allowing to stand so that the two liquids separate, 50 ml. of the aqueous layer are taken, the iodine liberated with sodium nitrite and titrated as in (i). 

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