164 UNIVERSITY OF COLORADO STUDIES. 



For these reasons it becomes necessary to modify the former formula 

 for thiochinanthrene by the addition of two hydrogen atoms. As will 

 be shown in the experimental part, this explains the fact that in every 

 case a too large amount of hydrogen was found to agree with the old 

 fonnulas. 



All compounds of this class add four molecules of nitric 

 acid, namely two on the nitrogen of the quinoline and two on 

 the sulphur atoms. Sulphuric acid salts are also formed in that 

 the bases unite with two molecules of the acid. In the cases 

 of hydrochloric and hydrobromic acids, it was not possible to 

 obtain tetrachlorides and tetrabromides. The bases enter into a 

 peculiar reaction with bromine. They all add bromine in acetic acid 

 solution. The bromine compounds thus formed are exceedingly un- 

 stable and give up bromine rapidly as soon as the crystals are re- 

 moved from the mother liquor. Since it is not possible to dry the 

 crystals quickly enough, it is possible only to obtain approximate 

 analyses of them. By heating the bromine products one does not 

 obtain, as might perhaps be expected from the Claus-CoUischonn re- 

 action, bromine substitution products; on the other hand the com- 

 pounds pass gradually, through loss of bromine, over into the hydro- 

 bromic acid salts, and finally, through loss of hydrobromic acid, into 

 the original bases. These facts would indicate that the bromine was 

 added to the sulphur atoms and the hydrobromic acid to the nitrogen 

 of the quinoline rest, an assumption which would fully agree with 

 the conclusion arrived at in regard to the constitution of the com- 

 pounds. In the case of thiochinanthrene, it was possible, by the 

 driving oS of bromine, to obtain the hydrobromic acid salt chem- 

 ically pure, as shown by the analysis. 



Experiments were also tried with the purpose of replacing the 

 sulphur hydrogen by means of acetyl. The attempts were all un- 

 successful, although at first it was supposed that bodies of this kind 

 were obtained. 



In the reaction of SClj upon paratoluquinoline, there are obtained 

 as by-products to the main reaction (which is the formation of the 

 sulphur body) chlorine substitution products. In these products the 



