Ryan & Cqllinane — Action of Oxides of Nitrogen onDiphenylene Oxide. 323 



In our experiments, which M'ere for the most \yAvi carried out at the 

 ordinary temperature and at low concentrations, the action upon diphenylene 

 oxide of the oxides and oxyacids of nitrogen was investigated. 



Nitrogen peroxide vapour converted diphenylene oxide into a dinitro 

 derivative, melting at 245° C. In glacial acetic acid solution the main product 

 was, however, a mononitrodiphenylene oxide, melting at 182° C. Under the 

 same conditions in carbon tetrachloride solution the mononitro and the dinitro 

 derivatives were formed. 



Nitrous fumes, when passed into a solution of diphenylene oxide in glacial 

 acetic acid, gave the mononitro compound, and, in addition, a small quantity 

 of the oxide was recovered. 



The treatment of diphenylene oxide directly with fuming nitric acid caused 

 the formation of a mixture of the mononitro and the dinitro derivatives. 



When dilute solutions of diphenylene oxide in glacial acetic acid were 

 treated with 1 and 4 molecular amoiints of fuming nitric acid, respectively, 

 and the solutions were allowed to remain at the room temperature for 5 months, 

 there was no appreciable action, the oxide being recovered unchanged in each 

 case. In similar experiments carried oiit Avith carbon tetrachloride as the 

 solvent mononitrodiphenylene oxide was formed. 



By heating solutions of diphenylene oxide in glacial acetic acid, or carbon 

 tetrachloride, with small amounts of fuming nitric acid, very good yields of 

 mononitrodiphenylene oxide were obtained. 



Dinitrodiphenylene oxide, melting at 245° C, was prepared most 

 conveniently by the action of fuming nitric acid on the mononitro compound 

 in glacial acetic acid solution. 



Trinitrodiphenylene oxide was not formed in large yield by nitration. By 

 treating the mononitro compound directly with fuming nitric acid a small 

 quantity of trinitrodiphenylene oxide, melting at 223° C, was isolated in 

 addition to the dinitro derivative. It is probable that this trinitro compound 

 is 1-3-6-trinitrodiphenylene oxide. In this reaction a small quantity of a tetra- 

 nitrodiphenylene oxide was also formed, but the best method of obtaining -the 

 latter body is by the direct action of a mixture of fuming nitric and concentrated 

 sulphuric acids on the dinitro compound. The tetranitrodipheuylene oxide 

 melted at 283° C, and is probably 1-3-6-8-tetranitrodiphenylene oxide. Recently 

 Borsche and Scholten [Ber. Dtsch. Chem. Ges., 1 (1917), p. 607] claim to have 

 obtained 1-3-6-8-tetranitrodiphenylene oxide, melting at 2525° C. 



Attempts to convert the tetranitro compound into a more highly nitrated 

 derivative were unsuccessful. 



Our results may be summarised as follows : — 



Diphenylene Oxide 



(M.P. 81°C.) 



I 



-~\ 



\1/ 4/ 



Nitrodiphenylene Oxide >■ DiuUroaiplienyleue Oxide 



(M.P. 18i°C.) 



i 



(M.P. 245° C.) 



TrinitrodipheiiYleiie Oxide ' >- Tetranitrodiphenylene Oxide 



(M.P. -223° C.) (M.P. 283' C.) 



Experimental. 

 1. Action of Nitrogen Peroxide on Diphenylene Oxide. 

 (a) In the Absence of Solvents.— 2 g. of diphenylene oxide and some dry 

 liquid nitrogen peroxide were placed in shallow dishes under a bell- jar. After 



