429 



a hoiling-poiiit of 250.5 — 251° at 73(> mm., wliicli does not solidify 

 at — JÜ°. 



Tiie yield of N («-pyridyi) pyrrole was in our experiments from 

 7 to 8 gr. out of 25 gr. of «-aminopyridine. 



We found, however, that there is formed another substance 

 besides this pyrrole derivative in the reaction between mucic acid 

 and amino pyridine. During the distillation of the I'caction product 

 a liiiuiil went over at 170°— IW^ and 15 mm., which cryslallized 

 at room temperature. After recrystallisation from alcohol this 

 substance had a melting-point of 95°, and appeared lo l)e <(-?'- 

 dipyritlyl amine. The formalion of this compound during the healing 

 of the mncic acid salt of amino i^yridine seems to be analogous to 

 the formation of diphenylamine fiom aniline and hj'drochloric aniline. 



We have actually obtained ^(-((-di|)yridyl amine by healing 

 equivalent quantities of <!-amino |)yridiiie and the hydrochloric acid 

 salt of this base in a sealed tube for two hours at 300^". We hope 

 lo return to this reaction on another occasion. 



^ 3. The conversion oj ^^{a-pijvuhjlypiin-oh into two isomeric 

 C ((t-j>i/ri(lijl)-jii/rroles. 



It was found long ago by Ciamician ') and his collaborators that 

 the N-derivatives of pyrrole can be iransformed into C-derivatives by 

 the action of high temperatures. 



Ciamician and Magnaghi ') heated N-acetyl pyrrole in a sealed 

 tube at 250 — 280° and found that part of the stalling material was 

 changed into pyrryl methyl ketone: 



HC CH HC CH 



HC CH -* HC C.COCH, 



N . COCH, NH 



That the acetyl rest actually occupies the «-position in the pyrrole 

 nucleus, results from the observation that the bromation pioduci ot 

 this pyrryl methyl ketone yields the imide of di-bromomaleic acid by 

 oxidation with nitric acid'). Also some other pyrrole derivatives, in 

 which an acylrest is combined with the nitrogen atom, were trans- 

 formed into «-|)yrrylketones on heating. 



It was found later by Pictkt and his collaborators that N-methyl 

 pyrrole, N-phenyl-pyrrole, and similar substituted derivatives of 



') Cf. Ciamician. Ber. d. deutsch. chem. Ges. 37, 4200 (1904). 



'-) Ibid. 18, 1828 (1885). 



5) Ciamician and Silbeb. ibid. 20, 2594 (1887). 



28* 



