IIyan & DoNNELLAN — AcUon of Oxides, &fc., on Dijyhenijlurethane. 115 



The solid, when recrystallised from alcohol, melted at 133°-134° C, and gave on 

 analysis the following results : — 



0-2363 g. of the substance gave 26-3 c.c. of moist nitrogen at 13-5° C.and 764 mm., 



corresponding to N 13'2. 

 CijH.sOeNj requires N 12-7. 



Its solution in cold alcoholic potash was at first colourless, hut on standing 

 gradually developed the violet coloration characteristic of 4-10-dinitro-dipheii)'l- 

 amine. The crystals dissolved in concentrated sulphuric acid, forming a yellow 

 solution, the colour of which was not affected by the addition of sodium nitrite. 



When the dinitro-urethane was heated with alcohoHc potash and the solution 

 vt^as diluted with water, a yellow solid was precipitated, which, when filtered, 

 washed, and recrystallised from alcohol, consisted of yelhjw crystals melting at 

 214°-216°C. The melting point was not affected by addition to the substance of 

 4T0-dinitro-diphenylamine, with which it was therefore identical. 



The dinitro-diphenylurethane melting at 133^-134° 0. was tlierefore the 

 4T0-dinitro-diphenylurethane already obtained by Hager (loc. cit.). 



i-lO-Binitro-dijihcnt/lurctJiane consists of acicular faint yellow prisms, which 

 are scarcely soluble in petroleum ether, soluble with difficulty in alcohol, soluble in 

 ether or chloroform, and very soluble in acetone. 



The brown oil, which was formed together with 4'10-dinitro-diphenylurethane, 

 and which has been mentioned above, did not crystallise. It was therefore 

 decomposed by heating with alcoholic potash, and the resulting diphenylaniine 

 derivative, when recrystallised from xyleiie, was obtained mainly in the form of 

 red crystals, which melted at 219° 0., and proved to be 2'10-dinitro- diphenylaniine. 



lll.—^Actio7i of a Midtire of Concentrated Sidphtoric and Nitric Acids. 



In this experiment five grams of diphenylurethane were added to a cold mixture 

 of 7 J c.c. of concentrated nitric acid and 15 c.c. of concentrated sulphuric acid. The 

 mixture became hot, with separation of a dark-coloured oily substance, and was 

 then heated on the water-bath for five or six hours. The brown solid which 

 separated on standing overnight, was freed from the acids by diluting the mixture 

 with cold water and filtering. Tlie solid was washed, dried, and recrystallised from 

 chloroform and alcohol. The yellowish-white crystals, thus obtained, melted at 

 184°-185° 0., and gave on analysis the following results: — 



0'1785 g. of the substance gave 25-8 c.c. of moist nitrogen at 19^ C. and 766'5 mm., 



corresponding to N 16'76. 



CioHnOioNs requires N 16'63. 



When this substance was heated with alcoholic potash a black, tarry mass was 

 obtained. It was, however, decomposed without resinification by heating it with 

 concentrated hydrochloric acid in a sealed tube to leO'-lSO" C. for eight hours. 

 The contents of the tube were neutralized with sodium carbonate, and the solid 

 reaction product was recrystallised from benzene. It consisted of light yellow 

 crystals, which melted at 198'-200" C, and proved to be identical with 2-4'8'10- 

 tetranitro-diphenylamine. 



The tetranitro derivative, which melted at 184°-185^ G., was therefore 2-4-8'10- 

 tetranitro-diphenylurethane. 



2'i-8'10-Tetranit7-o-diphenylurethcmc consists of yellowish-white platy prisms, 

 which are sparingly soluble in petroleum ether, cold alcohol, or ether ; soluble in 

 hot alcohol, cold chloroform, or benzene ; and readily soluble in acetone. 



