52 PROCEEDINGS OF THE AMERICAN ACADPJMY. 



Properties. — This tribromphenylurethane crystallizes from alcohol 

 and water in long slender white needles in radiating bunches forming a 

 thick felted mass. It melts at 101°; and is freely soluble in alcohol, 

 ether, benzol, chloroform, or glacial acetic acid; insoluble in water. 

 When it is heated with aniline it yields diphenylurea melting at 235°, 

 and the tribromaniline, which was recognized by its peculiar odor. Its 

 behavior, therefore, in this respect is like that of the tribromphenylure- 

 thane NH 1, Brg 3, 4, b, previously described in this jDaper. 



Tribromnitracetanilid, CeHBrsNO^NIICOCHs, NHl, Br^ 2, 4, 5. 



This substance was prepared from the corresponding acetanilid de- 

 sci'ibed in our previous paper.* We have not determined the position 

 of the nitro group, but should suppose it would be ortho to the acetamido 

 group, and therefore 6. Five grams of the tribroraacetanilid were added 

 in small portions at a time to about forty grams of nitric acid of specific 

 gravity 1.50. The mixture was allowed to stand an hour at ordinary 

 temperatures, and then poured into a large volume of cold water ; the 

 precipitate was recrystallized from alcohol, until it showed the constant 

 melting point 228°, when it was dried at 100°, and analyzed with the 

 following result : — 



0.1001 gram of the substance gave 0.1348 gram of argentic bromide 

 by the method of Carius. 



Calculated for CoHBrsNOjNHCOCUj. Found. 



Bromine 57.55 57.33 



Properties. — This tribromnitracetanilid crystallizes from hot alcohol 

 in little branched needles generally arranged in circular radiating groups, 

 or in sheaves. It was pinkish white, but is probably white when per- 

 fectly pure. It melts at 228° ; and is freely soluble in ether, benzol, 

 chloroform, carbonic disulphide, or glacial acetic acid. Sulphuric acid, 

 when boiled with it, converts it into the tribromnitraniline described 

 below. 



Tribromnitraniline, CoHBrsNOoNH., NILl, Brg 2, 4, 5. 



Ten grams of the tribromnitracetanilid were heated in a flask with a 

 return condenser with sulphuric acid diluted to the specific gravity 1.44, 

 until the solid went into solution. The solution after it had cooled was 

 diluted with water, neutralized with dilute sodic hydrate, and the brownish 

 precipitate purified by recrystallizatiou from alcohol. When it showed 



* Amer. Chem. Journ., XVIII. 249. 



