Ryan & Cullinane — Action of Oxides, Sfc, on Ethyl-o-Tolylur ethane. 121 



melting at 159°-160° C. In like manner, 4-nitro-2-methyl-phenylurethane on 

 interaction with fuming nitric acid produced the same substance. The dinitro 

 compound was therefore 4'6-dinitro-2-methyl-phenylurethane. 



Experimental. 



k.— ACTION OF THE OXIDES AND THE OXY ACIDS OF NITROGEN ON 

 ETHYL- 0- TOL YL URETHA NE. 



I. — Nitrogen Peroxide. 



(a) Action in the VcqMur Phase. — Ten grams of ethyl-o-tolylurethane and 

 dry, liquid nitrogen peroxide were placed in shallow dishes side by side under a 

 bell jar. Fresh quantities of nitrogen peroxide were added when necessary from 

 time to time. In a few days crystals were deposited from the red liquid, and, 

 after five weelis standing, the mother liquid, which had acquired a reddish-brown 

 colouration, and was strongly acid in reaction, was poured off, and the crystals 

 were washed with petroleum ether. On recrystallisation from alcohol almost 

 colourless crystals were deposited in the form of large prisms, melting at 135° C. 

 A further quantity was obtained by adding alcohol to the acid mother liquid, and 

 allowing the mixture to stand for a few days. On analysis the following results 

 were obtained : — 



0-1741 g. of the substance gave 18-5 c.c. of moist nitrogen at 14° C. and 760 mm., 



corresponding to N 12'5. 

 CioHijOiNa requires N 12'5. 



4:-Nitro-2-methyl-phcnylnrethane is soluble in most organic solvents, somewhat 

 soluble in boiling water, and slightly soluble in petroleum ether. 



When one gram of the substance was heated with 100 c.c. of concentrated 

 hydrochloric acid under a reflux condenser for four hours, the nitro compound 

 was decomposed with the formation of 4-nitro-2-methyl-pheny]amine. A few 

 crystals of oxalic acid were also isolated. 



(b) Action in the Presence of Solvents. — A solution of 5 g. of ethyl-o-tolyl- 

 urethane in 20 g. of carbon tetrachloride, saturated with nitrogen peroxide, was 

 allowed to remain at the room temperature for four months. At the end of that 

 period the solution had an orange-red colour and contained some crystals of oxalic 

 acid. Most of the urethane was, howevei-, recovered unchanged. 



Similar experiments were performed with solutions of the urethane in ether 

 and glacial acetic aci<l, and with similar negative results. 



II. — Nitrous Fumes. 



Experiments resembling those just described were performed with solutions 

 of the urethane in carbon tetrachloride and glacial acetic acid, and the nitrous 

 fumes generated by the action of arsenious oxide on nitric acid. Again, although 

 a small amount of oxalic acid was formed, most of the urethane was recovered 

 unchanged. 



B.~AGTION OF NITRIC ACID ON ETHYL-O-TOLYLURETHANE. 

 I. — Concentrated Nitric Acid. ' 



On the addition of concentrated nitric acid (sp. g. 1-4) to ethyl-o-tolylurethane 

 there was no separation of solid matter, and, even after heating on the water- 

 bath for several hours, two layers remained. When the mixture was poured into 

 water the only product obtained consisted of unchanged ethyl-o-tolylurethane. 



