Ryan & Donnefxan — Action of Oxides, ^'c, on Diphenylurethane. Ill 



The oil formed by the action of nitric acid on the urethane was a solution of 

 4-10-dinitro-diphenyliu-ethaiie in 2-10-dinitro-diphenyluretliane. 



(4) The behaviour of a solution of diphenylurethane in carbon tetrachloride, 

 to which a quantity of nitric acid corresponding to six molecular proportions of 

 the acid had been added, was quite similar to the last— the products formed in 

 this case being also 4-10- and 2-10-dinitro-diphenylurethanes. 



B.— ACTION OF NITRIC ACID ON i-DINITRO-BIPHENYLURETHANE. 



(1) 4-Nitro-diphenylurethane (1 gram) was added slowly with constant 

 shaking to 4 c.c. of concentrated nitric acid (sp. g. 1-42). The solid dissolved, 

 forming a yellow solution. On examining it after two days it was found that the 

 nitric acid had not reacted with the nitro-urethane, which was recovered 

 unchanged. 



(2) One gram of 4-nitro-diphenylurethane was added to a cold mixture of 4 c.c. 

 of concentrated nitric acid and 8 c.c. of concentrated sulphuric acid. The solution 

 was allowed to stand at the temperature of the room for two days. On pouring it 

 into water a white solid separated, which, when recrystallised from chloroform, 

 melted at 184°-185° C, and proved to be 2-4-8T0-tetranitro-diphenylurethane. 



Hence 4-nitro-diphenylurethane on nitration by "mixed acids" in the cold 

 goes into 2*4'8-10-tetranitro-diphenylurethane. 



C— ACTION OF NITRIC ACID ON 2'i'8-\0-TFTRANITRO- 

 DIPIIENYL UR E THA NE. 



One gram of tetranitro-diphenylurethane was added slowly to a cold mixture 

 of 4 c.c. of concentrated nitric acid and 8 c.c. of concentrated sulphuric acid, 

 which was then heated on the water-bath for about seven hours. On standing 

 overnight a yellow solid separated. The mixture was diluted with water, and the 

 solid was crystallised from chloroform, in which it was only sparingly soluble. It 

 consisted of yellow prisms, which melted at 246° C, and were found to be identical 

 with 2-4-6-8-10-12-hexanitro-diphenylamine. 



D.~ ACTION OF NITROGEN PEROXIDE ON DIPHENYLURETHANE. 



A stream of nitrogen peroxide (generated by heating lead nitrate) was passed 

 into a solution of two grams of diphenylurethane in fifty grams of carbon tetra- 

 chloride. The yellow solution became wine-coloured on standing at the tempera- 

 ture of the laboratory, and at the end of a week a brown oil separated. The 

 solution was again saturated with nitrogen peroxide. When the solution remained 

 at the laboratory temperature for a fortnight, the carbon tetrachloride was dis- 

 tilled off, and a brown oil was left behind.' As the oil did not crystallise, it was 

 boiled with alcoholic potash for an hoar; the mixture was diluted with water, 

 and the solid which separated was filtered and dried. When heated with chloro- 

 form part of the solid dissolved; the solution was filtered while hot, and from it 

 4-10-dinitro-diphenylamine, melting at 214° C, was deposited on cooling. The 

 portion which remained undissolved was crystallised from benzene, from which 

 tt separated in the form of red crystals, melting at 219° C, and which were 

 identical with 2'10-dinitro-diphenylamine. 



SCIENT. PEOC. K.D.S., VOL. XVII, NO. 14. X 



