114 M. Hlasiwetz and Gilm on Hydroberberine. 



In its formation, piperidine simply assimilates nitrous acid and 

 liberates water, which, acting upon some nitrous acid, produces 

 nitric acid. The following equation expresses both phases of the 

 action : — 



G 5 H 11 N + 2N 2 O s = G 5 H l0 N 2 O + NO s H + 2N9. 



Piperidine. Nitrous New body. Nitric acid, 



acid. 



The body is thus piperidine in which hydrogen is replaced by 

 binoxide of nitrogen, and it may be named Nitroxylpiperidine. 

 By the action of nascent hydrogen, the binoxide can be removed 

 and replaced by hydrogen, and the original body restored. The 

 same change may be effected by hydrochloric acid. When 

 nitroxylpiperidine is heated to 100° in a current of this gas, it 

 is first changed into a crystalline mass, which by the further 

 action of the acid is again liquefied ; and on continuing the action, 

 maintaining the temperature at 100° C, a yellow gas is dis- 

 engaged, and a crystalline mass left. This was found to be 

 hydrochlorate of piperidine, and a careful investigation of the 

 gas showed that it was chloronitrous acid. The formation of 

 these two substances is thus expressed : — 



G 5 H 10 N 2 + 2HC1=€ 6 H 11 N,HC1 + NOC1. 



Nitroxyl- Hydrochlorate Chloronitrous 



piperidine. of piperidine. acid. 



By the substitution of binoxide of nitrogen for hydrogen, the 

 basic properties of the piperidine are greatly diminished, yet not 

 entirely destroyed ; for direct experiments of Wertheim showed 

 that the substance probably absorbed a quantity of hydrochloric 

 acid corresponding to one equivalent, forming a crystalline body. 



Hlasiwetz and Gilm* have described a hydrogenized deriva- 

 tive of berberine obtained by the action of nascent hydrogen 

 upon that base. In a spacious flask connected with a condenser, 

 a mixture is introduced of berberine, water, pure sulphuric acid, 

 glacial acetic acid, a large quantity of zinc, and a few pieces of 

 platinum, and the whole heated to boiling. The original dark 

 golden colour of the solution becomes gradually lighter ; and the 

 reaction is interrupted when no further change takes place, 

 which is generally after the lapse of one or two hours. The 

 best method of obtaining the new product consists in filtering 

 this liquid, and adding to the filtrate an excess of a saturated 

 solution of common salt, by which the new body is entirely 

 deposited as hydrochlorate in the form of a very difficultly soluble 

 precipitate. This is washed and pressed, dissolved in boiling 

 alcohol, and ammonia added. On cooling, the new base crystal- 



* Liebig's Annalen, Supplement, vol. ii. No. 2. 



