THE IMIDES OF THE AR03IATIC SÜLPHONIC ACIDS. 19 



thrown down from wliicli the free acid was obtained in the crys- 

 talline state by decomposing it with hydrogen sulphide and eva- 

 porating the filtered solution in a vacuum desiccator at ordinary 

 temperatures. 



When the reaction between the dioxime and sulphur dioxide 

 is carried out in j^i'esence of absolute alcohol, the greater part of 

 amidosulphonic acid separates out in the form of crystals, having 

 the melting point of 205°C. The quantity of this acid estimated 

 from the amount of ammonia, formed on hydrolysis with hydro- 

 chloric acid at 150°C., after the removal of the isoxazol, showed 

 that the reaction took place quantitatively. 



Äcelonylacetonedioxime and Sulphur Dioxide : — Acetonyl- 

 acetonedioxime was dissolved iti about five times its weight of 

 water and treated with a current of sulphur dioxide. So much 

 heat was evolved that it required external cooling with water. 

 On leaving the mixture over night, and then expelling the ex- 

 cess of sulphur dioxide and evaporating the solution in a vacuum 

 desiccator, an oily product was left mixed with crystals of amido- 

 sulphonic acid. On now treating the mixture with alcohol, the 

 oily substance dissolved away, leaving behind the amidosulphonic 

 acid. The quantity of this acid thus obtained was a little more 

 than half of that calculated for one molecule of the acid from 

 one molecule of the dioxime used. 



The oily substance was soluble in water and in alcohol, but 

 insoluble in ether. It could be neither brought into the crystal- 

 line state, nor obtained as compounds with other substances suf- 

 ficiently pure for analysis. Attempts to reduce it to the corres- 

 ponding amine by stannous chloride and hydrochloric acid gave 

 no satisfactory result. An aqueous solution of the substance did 

 not reduce Fehling's solution in the cold, but did so strongly. 



