324 Scientific Proceedings, Royal Dublin Society. 



remaining at the room temperature for a day the oxide assumed a yellow colour, 

 which deepened slightly as the reaction progressed. The experiment was 

 continued for 5 weeks, the supply of nitrogen peroxide being only once 

 replenished, as its absorption was slow. The yellow product was washed with 

 ligroiu, and, after reerystallisation from glacial acetic acid, fine white needles, 

 melting at 245° C, separated in a very good yield. This compound was there- 

 fore evidently identical with the dinitrodiphenylene oxide obtained by Mailhe by 

 the action of nitric acid on the oxide. 



(fo) In Glacial Acetic Acid Solution. — 1 g. of diphenylene oxide was dissolved 

 in 20 c.c. of glacial acetic acid, and dry nitrogen peroxide vapour was passed 

 into the solution until the latter was saturated. The reddish-brown solution 

 was allowed to remain in a stoppered bottle at the room temperature, a 

 relatively large quantity of a yellow solid being deposited overnight. After 

 3 months the product was poured into water; the yellow solid was washed 

 free from acid, and after reerystallisation from glacial acetic acid it consisted 

 of yellow sUky needles, melting at 182° C. It was evidently identical with 

 the mononitrodiphenylene oxide obtained by Borsche and Bothe {loc. cit.), by 

 the action of fuming nitric acid on a solution of diphenylene oxide in acetic 

 acid. 



(c) In Carbon Tetrachloride Solution. — A solution of 2 g. of diphenylene 

 oxide in 40 g. of carbon tetrachloride was saturated with nitrogen peroxide 

 vapour. Some heat was evolved, and on cooling a yellow solid was deposited. 

 The mixture was allowed to remain at the room temperature for 3 months. 

 The solvent was then evaporated, and the solid product was extracted several 

 times with boiling alcohol until only a very small amount of residue was left. 

 From the filtrate a good yield of the above-mentioned mononitro derivative 

 was obtained, while the residue on reerystallisation from glacial acetic acid 

 gave a small quantity of dinitrodiphenylene oxide, melting at 245° 0. 



2. Action of Nitrous Fumes on Diphenylene Oxide. 



Nitrous fumes, generated by the action of arsenious oxide on nitric acid, 

 were passed into a solution of 2 g. of diiDhenylene oxide in 40 g. of glacial 

 acetic acid. After remaining at the room temperature a small quantity of 

 a yellow solid was deposited from the dark-green solution, and this increased 

 gradually in amount. After 4 weeks the solution was filtered from the solid 

 residue, which on crystallisation was found to be the mononitro derivative 

 already described. The filtrate on evaporation gave a further yield of this 

 substance in addition to some unchanged oxide. 



3. Action of Fuming Nitric Acid on Diphenylene Oxide. 



(ft) In the Absence of Solvents. — 2 g. of diphenylene oxide was added 

 gradually to fuming nitric acid (10 c.c). A ^dgorous reaction ensued, and 

 a yellow solid was obtained on cooling the mixture. This solid was washed 

 with water, dried, and extracted with boiling ligroin, and finally with boiling 

 alcohol. The undissolved residue consisted of dinitrodiphenylene oxide, melting 

 at 245° C, and from the alcoholic filtrate the mononitro compound, melting 

 at 182° C, was isolated. 



(b) In Glacial Acetic Acid Solution. — To two solutions, each of which 

 contained 1 g. of diphenylene oxide in 100 g. of glacial acid, 1 and 4 molecular 

 amounts of fuming nitric acid were added respectively. The reactions were 

 evidently very slight, even on allowing the solutions to remain at the room 

 temperature for 5 months, since the only substance isolated was, in both cases, 

 the original oxide. 



