Ryan & O'Toole — Action of Oxides, Sfc, on the Phenyliireas. 141 



concentration gave, with one, two, four, and six molecular amounts of nitric acid, 

 only phenylurea nitrate, wliich melted with decomposition at 131° C. 



This compound is described by Pickard and Kenyon [Trans. Chem. Soc, 1907, 

 p. 902], who obtained it by cooling a warm concentrated nitric acid solution of 

 phenylurea. It crystallised as colourless leaflets, melting with decomposition at 

 134°-135° C. 



In carbon tetrachloride suspension phenylurea nitrate was obtained with one, 

 two, and four molecular amounts of nitric acid. In the latter case traces of 

 p-nitro-phenylurea [Eeudler, he. cit.~] were obtained. With six molecular amounts 

 of nitric acid it gave 2-4-dinitro-phenyl-nitro-urea. 



Phenylurea in carbon tetrachloride suspension interacted with both nitrous 

 fumes and nitrogen peroxide at room temperature, giving in each case ortho- and 

 paranitro phenol, with an evolution of gas. 



K.— ACTION OF NITROUS FUMES ON PHENYLUREA. 



Phenylurea (10 g.) was suspended in 200 g. of carbon tetrachloride, and the 

 mixture was saturated at the room temperature with the nitrous fumes evolved 

 from arsenious oxide and nitric acid. After some time a brisk evolution of gas 

 was observed, and the substance assumed a greenish colour; but later all the solid 

 was converted into a brownish-black oil with a further evolution of gas and some 

 heat. After allowing to remain at room temperature overnight the carbon tetra- 

 chloride was distilled off under reduced pressure from the yellowish-brown solution, 

 and the black oil which remained was distilled with steam. In the distillate was 

 found a substance consisting of yellow needles melting at 40° C. It proved to be 

 ortho-nitrophenol, a mixture of this substance with it also melting at the same 

 temperature. 



The residue after the steam distillation consisted of a black oil. This was 

 extracted several times with boiling water, and the united extracts boiled down to 

 small bulk. It was then made alkaline with sodium hydroxide, boiled with 

 animal charcoal, and evaporated still further. By acidifying with hydrochloric 

 acid a small quantity of a substance was obtained. This, after crystallisation 

 from a small quantity of alcohol, consisted of colourless needles melting at 114° C, 

 and, as a mixture of it with p-nitrophenol also melted at the same temperature, 

 it must have been identical with the latter substance. 



^.—ACTION OF NITROGEN PEROXIDE ON PHENYLUREA. 



Phenylurea (5 g.) was suspended in 100 g. of carbon tetrachloride, and nitrogen 

 peroxide was passed into the mixture until it was saturated at room temperature. 

 The phenylurea was converted into a black oil with the evolution of gas and heat. 

 After allowing the mixture to remain overnight at the temperature of the room, 

 ortho- and paranitro phenols were isolated from it by methods similar to those 

 described above. 



C— ACTION OF NITRIC ACID ON PHENYLUREA. 



I.— In the Presence of Solvents. 



(a) Glacial acetic acid. — One, two, four, and six molecular amounts of nitric 

 acid were added respectively to four bottles each containing 5 g. of phenylurea 

 dissolved in 100 g. of glacial acetic acid. The mixtures were allowed to remain at 

 the temperature of the room for two months in well-stoppered bottles. 



2d2 



