Rosolic Acid and Rosaniline, 131 



tested by heating them with iodine, mercuric chloride and 

 arsenic acid, and gave only the minutest trace of rosaniline. 



Iodoform* was heated gently with this pure aniline. It dis- 

 solved, and almost immediately afterwards gave rise to an ener- 

 getic reaction, the mixture darkening rapidly, and then solidify- 

 ing from the formation of hydroiodates of aniline and rosani- 

 line, the latter being produced in great abundance. 



Under similar conditions toluidine is attacked violently, 

 giving a brown-coloured product which contains no rosaniline. 



Similar results were obtained by heating pure aniline with 

 iodine and formiate of lead; and the formation of rosaniline was 

 likewise, although less strikingly, observed by the action of 

 chloroform, chloride of carbon, and iodide of cyanogen upon, 

 pure aniline. 



The bearing of these experimental results on the theory of the 

 constitution of rosolic acid and rosaniline will be obvious. Both 

 of these substances appear to contain aromatic and fatty carbon, 

 and accordingly we see that, in order to form either of them, it is 

 necessary to have both a phenyle-compound and a fatty carbon- 

 compound present. This fatty carbon-compound may be cres- 

 sol or toluidine, which the researches of Tollens and Fit tig t 

 have shown to contain methyle ; or it may be a simpler member 

 of the fatty series, such as iodoform or oxalic acid. 



The subjoined equations, which may be regarded as expres- 

 sing the formations of rosaniline and rosolic acid, exhibit this 

 fact, and show the very close parallelism subsisting between 

 these formations : — 



Aniline. Toluidine. Rosaniline. 



14 C 6 H 7 N + 2C 7 H 9 N = C 20 H 19 N 3 + 6H. 



' 1I.§ C 6 H 5 (NH 2 ) + 2C 6 H 4 (CH 3 ) (NH 2 ) = C 20 H 19 N 3 + 6H. 



III. 3C 6 H 5 (NH 2 ) + 2C = C 20 H 19 N 3 + 2H. 



Phenol. Cressol. Rosolic acid. 



IV. C 6 H 6 + 2C 7 H 8 =C 20 H 16 3 + 6H. 

 V. C 6 H 5 (OH)+2C 6 H 4 (CH 3 )(OH) =C 20 H 16 O 3 + 6H. 



VI. 3C 6 H 5 (OH) + 2C =C 20 H l6 O 3 + 2H. 



Note. — The fact that neither pure aniline nor pure phe- 

 nol is attacked by arsenic acid or similar colour-forming rea- 



* Iodoform is one of the numerous reagents patented for the production 

 of aniline-red by Renard freres of Lyons. French patent dated Decem- 

 ber]?, 1859. 



t Ann. der Chem. und Pharm. vol. cxxxi. p. 304. 



X Hofmann, Proc. Roy. Soc. vol. xiii. p. 485. 



§ Kekule, Ann. der Chem. und Pharm. vol. cxxxvii. p. 146. 



K2 



