Ryan & O'Donovan — Action of Oxides, &,-c., on Phenyl-benzt/hirethane. 133 



Secondary oxidation reactions similar to those met in the case of ethyl-o- 

 Lolyhirethane or ethyl-phenylurethane could, and did, occur during the nitration. 

 It is very likely tliat 2'4-dinitro-phenylurethane and 4-nitro-henzoic acid were 

 formed by the oxidation and subsequent hydrolysis of 2-4'10-trinitro-phenyl- 

 benzylurethane. 



EXPEIUMENTAL. 

 A— ACTION OF NITROGEN PEROXIDM ON PHENYL-BENZyLVUETEANE. 



I. — In the Vapour Phase. 



rheuyl-benzylurethaue (10 grams) and liquid nitrogen peroxide (obtained by 

 the decomposition of lead nitrate) were placed in shallow vessels, side by side, 

 under a bell-jar. I'he urethane rapidly absorbed the nitrogen peroxide, which 

 was renewed from time to time ; its colour changed througli reddish-brown to green, 

 and after about ten days some long, colourless prisms were observed in the acid 

 oil. The crystals, whicli were left in the dish when the oil was removed by 

 nreans of chloroform, melted in the hydrated condition at 99°-101° C, and in the 

 anhydrous state at 189^ 0. They reduced potassium permanganate and consisted 

 of oxalic acid, which was probably formed by oxidation of the alcohol set free by 

 a partial liydrolysis of tlie urethane. 



The oil left after the evaporation of the chloroform partially crystallised on 

 prolonged standing. By meaiis of petroleum ether a crystalline solid was extracted 

 from the mixture, and this, when boiled with animal charcoal and alcohol, filtered, 

 and cooled, gave about 2 g. of long, rhombic crystals, having two truncated angles, 

 and melting at 110°-lll^O. It proved to be a trinitro-phenyl-henzylurethane ; a 

 mixture of it with 2.4-dinitro-phenylurethane, which also melts at 110°-111° C, 

 melted at 75°-80° C. It gave ou analysis the following results : — 



0'1348 g. of the substance gave 16-4 c.c. of moist nitrogen at 15'5° C. and 765 mm., 



corresponding to N" 14'4. 

 CijHuOsNj requires N 14-4. 



Trinitro-i^henyl-ienzyhorethane is readily soluble in ether, chloroform, nitro- 

 benzene, hot alcohol, and hot petroleum ether. On hydrolysis with alcoholic potash 

 it gave a very small amount of a brown solid, melting between 180° and 190° C, 

 from which we were unable to isolate any pure substance. 



The reddish oil from which the trinitro compound had been mechanically 

 removed was dissolved in boiling alcohol, from which it again separated as an 

 oil. Tliis was dissolved in ether, .and by spontaneous evaporation of the solvent 

 about o g. of the 4-nitro-phenyl-benzylurethane, described later, on, were 

 obtained. 



II. — In Sohdion. 



(a') In glacial acetic acid. — Nitrogen peroxide vapour was passed through a 

 solution of 5 g. of phenyl-benzylurethane in 50 g. of glacial acetic acid. The 

 mixtui'e was allowed to remain for some months in a stoppered flask, the supply 

 of nitrogen peroxide being renewed twice as the reaction progressed. The yellow 

 oil which separated when the mixture was poured into water was dissolved in 

 hot alcohol. By cooling the solution and inoculating it with a couple of crystals 

 of 4-nitro-phenyl-benzylurethane and 10-nitro-phenyl-benzylurethane, about one 

 gram of the former substance was obtained in a pure condition. 



