22 Dr. E. J. Mills on Aniline Derivatives. 



acetate for some hours so as to form acetanilide, which is then 

 purified hy crystallization. The acetanilicle is powdered, sus- 

 pended in water, and treated with excess of bromine or chlorine 

 (Proc. Roy. Soc. vol. x. p. 589) : the product is heated with 

 powdered potash, moistened with spirit. This method gives good 

 results. The product consists chiefly of mono- and tri- deriva- 

 tives. 



(13) It is not necessary to prepare acetanilide ; a solution of 

 dry aniline in glacial acetate answers equally well. Aniline is 

 dissolved in 2-3 vols, of acetate, and chlorine- or bromine- 

 vapour passed over the surface of the mixture, which must be 

 well agitated. [In the case of bromine-vapour, the operation is 

 performed in a warm closet, and the bromine is volatilized slowly 

 from a retort, which must be heated by a small flame placed a con- 

 siderable distance below. It is very easy thus to manage so that, 

 while vapour comes over freely, no drops of bromine are delivered 

 from the tube of the retort. This tube should be bent vertically 

 downwards, and nearly touch the surface of the aniline mixture 

 in the flask where the operation is conducted.] Considerable 

 heat is evolved at first. As the reaction proceeds, the mixture 

 becomes thicker, and partially solidifies; and at this point the 

 operator will arrest it if he requires a minimum of tri- derivative, 

 but continue until total solidification ensues if he wishes the tri- 

 derivative to be a maximum. The whole may, if desired, be again 

 submitted to further action by gently heating with more glacial 

 acetate, which causes solution to occur. The cooled mass is 

 heated to 100° under water, and afterwards cooled therewith. 

 The supernatant liquid is filtered off and precipitated with alkali : 

 this precipitate contains mono- and di- derivatives. The inso- 

 luble portion is mixed with powdered potash, moistened with 

 spirit, and then heated in order to destroy any traces of anilide 

 that may have been formed. The three derivatives are separated 

 from the dark mass as already stated. The distinguishing fea- 

 ture of this mode of reaction is, that it is completely under the 

 control of the experimenter. The ratio C 8 H 9 ON : Br 2 furnishes 

 chiefly dibromaniline. Doubtless this process applies to other 

 amines. 



(7) The direct action of chlorine &c. on aniline itself is not 

 attended with satisfactory results; in presence also of water or 

 aqueous hydric salt there is an enormous amount of by-product. 

 Aniline purified by distillation with mercuric iodide yields ex- 

 ceedingly little moniodaniline. 



(S) Aniline may be mixed with plumbic oxide, and iodine &c. 

 added"*. I have only succeeded in preparing traces of iodaniline 

 in this way. A considerable amount of crude product is obtained, 

 * This is Stenhouse's method ofiodating orcin. 



