384 CONSIDERATION OF CARBON COMPOUNDS. 



the constitution of which is represented in the formula 



It is obtained by boiling together for one or two days equal weights 

 of pure aniline and glacial acetic acid, distilling and collecting the por- 

 tion which passes over at a temperature of about 295 C. (5,63 F.). 

 The distillate solidifies on cooling and may be purified by recry stall iza- 

 tion from solution in water. The chemical change taking place is this : 



C 6 H 6 NH 2 + C 2 H 4 2 == C 6 H 5 .NH.C 2 H 3 + H 2 O. 



Pure acetanilid forms white, odorless crystals of a silken lustre and 

 a greasy feeling to the touch. It fuses at 113 0. (235 F.) and boils 

 at 295 C. (563 F.) ; it is but slightly soluble in cold, much more 

 soluble in hot water, readily soluble in alcohol and ether ; the solu- 

 tions have a neutral reaction and are not colored by either concen- 

 trated sulphuric acid or by ferric chloride. 



Analytical reactions: 



1. When 0.1 gramme acetanilid is boiled with 1 c.c. hydrochloric 

 acid and to this solution is added 1 c.c. each of saturated solutions of 

 carbolic acid and of bleaching powder, a turbid red liquid is obtained 

 which turns dark-blue when supersaturated with ammonia water. 

 (Plate VI., 6.) 



2. On heating 0.1 gramme of acetanilid with a few c.c. of concen- 

 trated solution (1 in 4) of potassium hydroxide, the odor of aniline 

 becomes noticeable ; on now adding chloroform, and again heating, 

 the disagreeable odor ,of the poisonous phenyl-isonitril, C 6 H 5 NC, is 

 evolved. 



3. A mixture of equal parts of acetanilid and sodium nitrite 

 sprinkled upon concentrated sulphuric acid produces a bright-red 

 color. 



Phenyl-hydrazine, C 6 H 5 .NH.NH 2 . Hydrazine compounds are substances 

 derived from the hypothetical body N 2 H 4 (or NH 2 NH 2 ) by replacement of 

 hydrogen atoms by alcohol radicals. They possess strong basic properties and 

 unite directly with acids, like amines or amides. Phenyl-hydrazine is of 

 interest because it is used in the manufacture of antipyrine, and also because 

 it is a valuable reagent for the detection of aldehydes and sugars. 



It is obtained by treating aniline chloride first with sodium nitrite, and then 

 with nascent hydrogen. It is an oily liquid forming white crystals at a low 

 temperature ; it is sparingly soluble in water, but readily in hydrochloric acid, 

 with which it combines to form the hydrochloride 



Antipyrine, C U H 12 N 2 O or C H 6 NO(CH 3 ) 2 N 2 O (Phenyl-dimethyl- 

 pyrazolori). When phenyl-hydrazine is heated with diacetic ether, 



