RvAN & O'TooLE — Action of Oxides, Sfc, on the Phenylureas. 143 



After extracting the nitrate completely in this manner a small quantity of a red 

 oil remained, from which no crystalline substance was obtained. 



(3) The bottle containing four molecular amounts of nitric acid had a yellow 

 solid in suspension and a yellow solution. The solution contained only a little 

 red oil. The solid, which melted with decomposition from 70°-80° C, on treat- 

 ment with cold water melted from 120°-160° C. The washing water contained 

 nitric acid. Some phenylurea was obtained from the residue. The original 

 substance, therefore, probably contained phenylurea nitrate. From the I'esidue 

 was also obtained a red crystalline substance, melting at 220° C. (uncorr.). This 

 was probably p-nitro-phenylurea. 



(4) The bottle containing six molecular amounts of nitric acid gave a yellow. 

 oily solid. The solution contained only a small amount of a red oil. The solid 

 was extracted with ether. The ethereal extract gave on evaporation a red oil, 

 from which no crystalline substance was obtained. The residue was dissolved in 

 acetone, and from the solution, by addition of petroleum ether, yellow needles 

 separated. These melted with decomposition at 155° C, and, when boiled with 

 water, dissolved with evolution of gas. The solution on cooling deposited red 

 needles, melting at 183° C, and consisting, probably, of 2-4-dinitraniline. 



An analysis of the original substance gave the following result : — 



0'0965 g. of the substance gave 21"8 e.e. of moist nitrogen at 19° C. and 758 mm., 



corresponding to N 25'91. 

 CHsOiNs required N 25-83. 



This substance was probably therefore 2'4-dinitro-phenyl-nitro-urea. 



II. — III the Absence of Solvents. 



Phenylurea (5 g.) was added in small quantities to twelve molecular amounts 

 of nitric acid, cooled in ice and salt. The phenylurea dissolved, and the nitric 

 acid became first yellow and afterwards red. Before all the phenylurea had been 

 added a solid began to separate from the acid in the form of colourless prisms. 

 On the addition of the remainder of the phenylurea more solid separated, and 

 the mixture was allowed to remain at room temperature overnight. It was 

 then filtered through glass wool, and the solid was washed with acetic acid and 

 ether. The product was colourless, and melted with decomposition at 164° (J. 

 (uncorr.). It was soluble in acetone and alcohol, from which it crystallised as 

 needles. Continued boiling with acetone gave it a permanent yellow colour, and 

 caused the melting point to fall. When it was dissolved in hot acetone and 

 then quickly cooled, colourless needles were obtained, decomposing at 16^ C. 

 (uncorr.). When boiled with water it dissolved, with the evolution of a gas, 

 giving a yellow solution, which, on cooling, deposited red needles, melting at 

 183° 0. (probably 2'4-dinitraniline). It was suspended in hot ether, and ammonia 

 was passed through the mixture for a quarter of an hour. The colour of the 

 suspended substance became bright yellow. It consisted of yellow needles, 

 melting at 200° C. (uncorr.) with decomposition, and was identical with 

 2-4-dinitro-phenylurea described by Keudler. 



An analysis of the original substance gave the following result : — 



"0638 of the substance gave 14 c.c. of moist nitrogen at 17° 0. and 768 mm., 

 corresponding to N 25'70. 

 CHsOiNs required N 25-83. 



The substance was therefore 2-4-dinitro-phenyl-nitro-urea. 



