124 Scientific Proceedings, Royal Dublin Society, 



IV. — 4:.Q-Dinitro-2-3fethyl-Phenylurethane. 



A solution of one gram of 4-nitro-2-methyl-phenylurethane in 5 c.c. of fuming 

 oitric acid was heated on the water-bath, with addition of further quantities 

 of the acid from time to time. After prolonged heating, the mixture was 

 cooled, and the white cake which was deposited was washed with water and 

 recrystallised from alcohol. The pure substance melted at ISQ^-IGO" C, and was 

 identical with the compound of similar melting point described in B — II. 



The nitration of 6-nitro-2-methyl-phenylurethane was performed in a similar 

 manner. After heating the mixture of fuming nitric acid and the nitro compound 

 for three days, the solution was poured into water. The purified product melted 

 at 159°-160°C., and was identical with the compound described in B— II. The 

 latter substance was therefore 4"6-dinitro-2-methyl-phenylurethane. 



Attempts to convert the 4-6-dinitro compound into a higher nitro derivative 

 were unsuccessful, the original substance being recovered in each case. 



V. — Action of Fuming Nitric Acid on Z-Nitro-2-Meth,yl-Plienylurethane. 



Two gTanis of 5-nitro-2-methyl-phenylurethane were heated on the water- 

 bath with 5 c.c. of fuming nitric acid, the reaction being allowed to proceed in 

 the usual manner. After two days the solid on cooling, on washing with water, 

 and recrystallising from alcohol, melted with decomposition at 193°-194''C. This 

 compound, which crystallised in the form of fine white needles, was readily 

 soluble in alcohol and ether, somewhat soluble in hot benzene and hot chloro- 

 form, almost insoluble in petroleum ether, and gave on analysis the following 

 results : — 



01604 g. of the substance gave 22 c.c. of moist nitrogen at 19° C. and 760 mm., 



corresponding to N 15"8. 

 CioHnOeNa requires N 15-6. 



The compound is therefore a dinitro-2-methyl-phenylurethane in which one 

 nitro radical is in the position 5, and the other is probably in the position 4. 



Summary. 



1. Ethyl-o-tolylurethane reacts with the oxides and the oxyacids of nitrogen 

 much less readily than diphenylamine. 



2. By the action of the oxides and the oxyacids of nitrogen on the urethaue 

 the ethyl radical is slowly eliminated, and the nitro products were in all cases 

 derived from o-tolylurethane. 



3. Nitrogen peroxide converted the urethaue into oxalic acid and 4-nitro- 

 2-methyl-phenylurethane, melting at 137° C, and identical with the product formed 

 by the action of ethyl chloroformate on 4-nitro-2-methyl-phenylurethane. 



4. In carbon tetrachloride solution fuming nitric acid converted ethyl-o- 

 tolylurethane into 4'6-dinitro-2-methyl-phenylurethane. The constitution of 

 the latter compound was determined by its formation by the further nitration of 

 either 4-nitro- or 6-nitro-2-methyl-phenylurethane. 



In conclusion we wish to state that the above research was undertaken on the 

 request of the Research Section of Nobel's Explosives Company, to whom we are 

 indebted for a grant in aid of the investigation. 



