BENZENE. 259 



ride precipitates from its alcoholic solution fine, yellow, 

 needly crystals of anilin platinum chloride, (C 6 IKN~. 

 HCl) 2 PtCl 4 . Anilin oxalate, 2(C 6 H 7 K)H 2 C 2 4 , crystal- 

 lizes from water in thick, hard prisms, is easily soluble 

 in hot water and hot alcohol, much less easily soluble 

 in the cold solvents. 



For the so-called anilin colors, see Toluidin. 



Substitution-products of anilin. In the ben- 

 zene residue of anilin one or more hydrogen atoms 

 may be replaced by the halogenes. These compounds 

 are formed by the action of chlorine, bromine, or iodine 

 on anilin ; by the decomposition of the substitution- 

 products of acetanilide and other anilides by means of 

 caustic potassa; by treating the mononitrochlorine, 

 bromine, or iodine substitution-products of benzene 

 with reducing agents ; by heating nitrobenzene with 

 concentrated hydrochloric or hydrobromic acids to a 

 high temperature ; and by the distillation of the sub- 

 stitution-products of isatine (see Indigo), with caustic 

 potassa. The basic properties of anilin are lessened by 

 the entrance of the halogenes. Trichlor- and tribrom- 

 anilin do not combine with acids. By heating anilin 

 with methyl alcohol under pressure at 300, the hy- 

 drogen of the benzene-residue can be replaced by 

 methyl CH 3 . 



Monochloranilin, C 6 H 4 C1.NH 2 . Is known in three 

 modifications. One of these (probably ortho), which 

 is obtained from the nitrochlorbenzene of fusing point 

 85, and from monochloracetanilide, forms shiny 

 octahedrons, insoluble in cold water, difficultly soluble 

 in boiling, easily in alcohol and ether. Fusing point, 

 64. Distills almost without decomposition. Both 

 the other modifications are liquid. Dichloranilin 

 C 6 H 3 C1 2 .KFI 2 , crystallizes in needles. Fusing point, 

 W.Trichloranilin C 6 H 2 C1 3 .KE 2 . Long, colorless 

 needles. Fusing point, 96.5 ; boiling point, 270. 

 Somewhat soluble in boiling water, easily in alcohol 

 and ether. Tetrachloranilin C 6 HC1 4 .NIP. Fine needles. 

 Fusing point, 90. 



