JACKSON AND CAI^VERT. — METAPHENYLENE DIAMINE. 1-19 



an excess of sodic hydrate, the precipitate thus formed dissolved in 

 hydrochloric acid, and reprecipitated with sodic hydrate in excess to 

 remove the hydrates of tin as completely as possible, and then extracted 

 with alcohol. The alcoholic extract deposited long white needles, 

 which melted at 78"-79°, and were therefore probably dibromaniline. 

 To establish the nature of the substance more fully, we tried the fol- 

 lowing experiments. The amido group was replaced b^ bromine, 

 when a product was obtained melting at 44°, the melting point of 

 the unsymmetrical tribrombenzol, and this when treated with nitric 

 acid was converted into the mononitrotribrombenzol melting at 93°. 

 There can be no doubt therefore that the tin and hydrochloric acid 

 have removed one of the atoms of bromine from the ortho position to 

 the amido group, replacing it by hydrogen. A quantitative experi- 

 ment gave the following results, — 10 grams of symmetrical tribroraani- 

 line yielded after reduction for six hours 5 grams of dibromaniline, from 

 which were obtained 5 grams of unsymmetrical tribrombenzol, and from 

 this 5.2 grams of tribromnitrobenzol. 



Dlhrommetaphenylene Dicetamide, C6H2Br2(NHC2H30)2. 

 "Whereas free metaphenylene diamine gives a tribrom derivative, 

 when treated with bromine water, we have obtained only the dibrom 

 compound from metaphenylene diacetamide, even when a considerable 

 excess of bromine was used. The samples analyzed were prepared by 

 the method given below, but a better method discovered later is de- 

 scribed after the analyses, — Metaphenylene diacetamide was dissolved 

 in common acetic acid with the aid of gentle heat, and treated at first 

 with bromine, and afterward with bromine water, until a slight excess 

 had been added. The new substance separated from the solution as it 

 was formed, and after standing a short time it was filtered out, and 

 purified by crystallization from hot glacial acetic acid until it showed 

 the constant melting point 259°, when it was dried at 100°, and ana- 

 lyzed with the following results : — 



I. 0.2471 gram of the substance gave 19 c.c. of nitrogen at a tem- 

 perature of 29° and a pressure of 754.3 mm. 

 11. 0.21 45 gram of the substance gave by the method of Carius 0.2294 



gram of argentic bromide. 

 III. 0.2033 gram of the substance gave by the method of Carius 0.2198 

 gram of argentic bromide. 



Calculated for Found. 



CeHjBroCNHCjHaO),. I. II. III. 



Nitrogen 8.00 8.33 



Bromine 45.71 45.52 46.01 



