Ryan & Duumm — Action of Oxides of Nitrogen on Diphenylether. 315 



A mixture of 472 g. of phenol, 24-8 g'. ol: potash, 62 8 g. of Ijromobeuzene, 

 and 04 g. of copper Ijronze was heated in an oil-bath under a reflux condenser 

 for 3 hours to a temperature which was gradually raised fi'om 190° C. to 

 230° C. When the reaction-product was distilled in a current of steam the 

 unchanged bromobenzene passed over first and was followed by the diphenyl- 

 ether, which quickl}^ solidified. The colourless crystalline diphenylether melted 

 at 28° C, and dissolved easily in the ordinary organic solvents. 



(b) 4-Nitrodiphenylether, which melted at 61° C. and dissolved easily in 

 ether or benzene, and moderately in cold alcohol or ligroin, was readily obtained 

 by the method of Haeussermann and Teichmann [Bar. Dtsch. Chem. Ges., xxix 

 (1896), p. 1446], in which 4-nitrochlorobenzene and potassium phenolate ai^e 

 heated in phenol solution to 150° C. for five hours. The product was freed 

 from phenol by washing it with aqueous alkali, and from excess of 4-nitro- 

 chlorobenzene by distilling the latter in a current of steam. The purified 

 substance was then reeiystallised from hot alcohol. 



(c) 2-4-Dinitrodiphenyl,eth€r was obtained from 2-4-dinitrochlorobeuzene and 

 potassium phenolate by the method previously' employed for its preparation by 

 Willgerodt [Ber. Dtsch. Chem. Ges., xxii (1879), p. 767; compare Maikopar, 

 ibid., vi (1873), p. 564]. It separated from alcohol in the form of long acicular 

 crystals, which melted at 71° C. 



(d) 210-Dinitrodiplienylether, which was previously obtained by Hausser- 

 mami and Bauer [Ber. Dtsch. Chem. Ges., xxix (1896), p. 2083], was prepared 

 by their method from 4-nitrochlorobenzene and the potassium derivatives of 

 2-nitrophenol. It consisted of colourless, acicular crj'stals, which melted at 

 103-5° C, and were sparingly soluble in cold, but easily in hot, alcohol. 



(e) 2-4-6-Trmitrodi-plienyletlier. — "Willgerodt [Ber. Dtsch. Chem. Ges., xii 

 (1879), p. 1278] obtained this bodj^ from picryl chloride and potassium phenolate. 

 We obtained it by a similar method. It melted, as Willgerodt states, at 153° C. 



(/) 2-4-10-Trinitrodiphenylether. — Following the method by which Willgerodt 

 and Huetlin first obtained this compound [Ber. Dtsch. Chem. Ges., xvii (1884), 

 p. 1765], we prepared it by heating the potassium derivative of 4-nitrophenol 

 with an alcoholic solution of 2-4-dinitrochlorobenzene in a sealed tube to 150° C. 

 for 6 hours. The pure compound consisted of thin six-sided, tabular ciystals, 

 which melted at 114° C, were soluble in hot alcohol, difficultly solulsle in 

 ether, and nearly insoluble in ligroin. 



2. Action of Nitrogen Peroxide on Diphenylether. 



(a) In the Absence of Solvenis. — Diphenylether (4 g.) and liquid nitrogen 

 peroxide were placed in shallow glass dishes, side by side, under a bell-jar, 

 and allowed to remain at the temperature of the room for a month. Initially 

 the absorption of the nitrogen peroxide was rapid, and this substance was, 

 therefore, renewed from time to time as required. The solid at first became 

 dark in colour and oily in consistency; it finally changed into a mixture of 

 a crystalline body with a dark-red oil. The nitrogen peroxide was removed 

 at the end of the month bj^ spontaneous evaporation, and the oily matter 

 was separated from the crystals by extraction with ether. The solid left 

 Tindissolved by the ether separated from hot alcohol in the form of colourless 

 needles, which melted at 103° C. As its melting-point was not aifected by 

 addition to the substance of 210-dinitrodiphenylether (prepared as described 

 above), the compound must have been identical with the latter body. 



When the ethereal solution of the oil was washed with potasli, the alkaline 

 layer became red in colour, and from it, by acidification, extraction with 



