Mr Crocker, On the interaction of Thiocyanates, etc. 347 



The interaction of Thiocyanates, Picric Chloride, and Alcohols. 

 By J. C. Crocker, B.A., St John's College. 



[Read 3 February 1902.] 



The action of picric chloride on lead and mercury thiocya- 

 nates in benzene and toluene solutions, was investigated by Dixon 

 (C. 8. J. 1896, 868). He could observe no reaction under these 

 conditions. When, however, picric chloride is allowed to act on 

 ammonium thiocyanate in absolute alcoholic solution a peculiar 

 reaction readily takes place. A yellow solid substance is formed 

 and hydrochloric acid is found in solution. 



10 gm. of picric chloride were dissolved in absolute alcohol and 

 the hot solution was mixed with a hot solution of 3"2 gm. ammo- 

 nium thiocyanate in absolute alcohol. The liquid almost imme- 

 diately became turbid and an oil separated out which quickly 

 solidified to a crumbling mass. On cooling, this was filtered off, 

 washed with water, alcohol and ether. The yield was 10 gm. 

 After recrystallisation from glacial acetic acid diluted with alcohol 

 (1:1) the product appeared as golden-yellow, compact, heavy 

 crystals, insoluble in water or ether, difficultly soluble in alcohol, 

 and easily soluble in glacial acetic acid. The crystals melted at 

 138°. Analysis gives the empirical formula C 15 H 9 N 7 S0 13 . 



The substance must thus contain two picryl groups, one of 

 which, as will be shewn later, is attached to a nitrogen atom. The 

 substance is very stable and undergoes changes with difficulty, its 

 stability towards reagents being probably due in some measure to 

 its insolubility in most solvents. When boiled with very concen- 

 trated potash, ammonia is evolved and ethyl alcohol can be de- 

 tected, by the iodoform reaction, in the distillate. The substance 

 is perfectly unchanged when heated to 100° for several hours, but 

 if the temperature is raised to 130° for a short time, the whole 

 mass is completely charred — owing to the high percentage of N0 2 

 groups contained in the body. 



The production of ethyl alcohol by potash distillation suggested 

 the presence of an ethoxy-group and the amount of this was 

 subsequently estimated by the Zeisel method, an additional bulb 

 of dilute CuS0 4 solution being interposed to absorb the sulphu- 

 retted hydrogen produced, the whole apparatus being kept at 

 85°— 90°. 



The view that has been taken with regard to the formation 

 and constitution of this body is as follows. The picryl chloride 

 and thiocyanate probably first react to form picryl thiocyanate, 



C 8 H 2 (N0 2 ) 3 - [CT\ + | "NH7| - S - C = N 



-C 6 H 2 (N0 2 ) 3 -S-C=N. 



