648 REPORT— 1887. 



CjjHogNOj + ILO = CglTi.NO + CgH,„03. 



In respect to the constitution of the last all doubts have been destroyed by a 

 research •which I have made in connection with my assistant, Dr. Eiigheinier. 

 We arrived to the first synthesis of this acid, and have fixed its formula to 



The nature of the basic component of the atropine had been quite obscure before 

 my researches. I could demonstrate in first line that tropine is not only a base 

 but also an alcohol, that it belongs to a class of compounds which I name alkines. 

 I proved this by forming etherical derivatives, the tropeines. These compounds 

 are produced by treating tropine with organic, especially aromatic, acids in presence 

 of dilute hydrochloric acid. In this manner atropine itself is formed by the action 

 of tropine on tropic and hydrochloric acid. In treating tropine by oxytoluic acid 

 in presence of hydrochloric acid homatropine is formed, a base very similar in its 

 physiological action to atropine, and of great value in the therapeutics of the eye. 

 Therefore we can suppose a group of liydroxvl in tropine and write its formula 

 C3H„(0H)N. 



The alcoholic nature of tropine comes still more to evidence in studying the 

 action of jodhydric acid and amorphous phosphorus on it. Diiodide of tropine 

 CgHjjNIo is formed. This substance comports itself like the jodhydrate of a base 

 containing iodine. The reaction is quite analogous to that which with nevrine 

 takes place — 



C,H,,NO + 2f]I = C5H,,,x,nir + H.,0 

 CgH^NO + 2HI = C8H,>',IIII + H;;0. 



The iodide of tropine treated with zinc-dust and cblorhydric acid is reduced 

 and yields the hydrochlorate of a tertiaric base, having the formula CgHj.N, which 

 I name hydrotropidine. It boils at 168° and is characterised by very fine salts. 



The hydrochlorate of this base distilled in a current of hydrochloric acid yields 

 chlorine of methyl and is transformed in the hydrochloride of a new base, which I 

 call norhydrotropidine, the composition of which is expressed by the formiJa 

 C,H,3N. We have CgHi.N IICl + IIUl = C^HijNHCl + CH.,C1. This base is crystal- 

 line, melts at 61°, and boils at 161°. It is a secondary base, which by the action 

 of nitrous acid is transformed into a nitrous amine melting at 117°. The hydro- 

 chlorate of this base is not deliquescent, and yields, by its distillation with zinc-dust, 

 hydrogene and a tertiaric base, which already by its smell is recognised to apper- 

 tain to the pyridine series. After purification I could prove the identity of this base 

 withaethylpyridine, which I have prepared synthetically in heating pyridine with 

 the iodide of ethyl. So that we can write the equation 



(C,II,3NIIC1), + Zn = ZnCl, + (O.IIgN), + H^o- 



We may conclude by these facts that norhydrotropidine is tetrahydro a ethyl- 

 pyridine and liydrotropidiiie v methyl a ethyltetrahydropyridine 



Cai,(C,H-,»)NC''H3. 



Tropine itself obtains the formula 



c,H,(c,I]/0II)^■c^I3•, 



and atropine 



C,II-(C.,n,000\ /CIl20H)NCHs 

 CH 



It is not impossible that the hydroxyl substitutes one atom of hydrogen in 

 the pyiidine group, but I think it not so probable as the supposition I made above. 



The synthesis of tropine must start from n ethylpyridine, and I made several 

 experiments in this direction, but till now without success. 



