RECENT WORK ON THE MORPHINE GROUP 283 



possible to replace the hydrogen atom united to the nitrogen,, 

 by a methyl group to form methylpiperidine. By treating 

 the latter with methyl iodide, dimethylpiperidylammonium 

 iodide is obtained, and this may be converted into the corre- 

 sponding hydroxide by the action of moist silver oxide. 

 When the dimethylpiperidylammonium hydroxide is subjected 

 to dry distillation, the piperidine ring is opened and water 

 splits off, leaving a substance named dimethylpiperidine. 

 This is a tertiary base, and can be combined with methyl 

 iodide to form dimethylpiperidylmethiodide, which again by 

 treatment with moist silver oxide yields the corresponding 

 hydroxide. If, now, the latter is strongly heated, it is de- 

 composed into water, trimethylamine, and a hydrocarbon 

 which Hofmann named piperylene. These reactions may be 

 illustrated as follows : 



CH, 

 CH 2 



CH, 



N 

 H 



CH, 

 CH, 



CH 

 CH, 



CH, 



N 

 CH, 



CH, 



CH 2 



CH, CH, 

 CH 2 CH 2 



CH 2 CH, 

 CH, CH 2 



N 



-' N 



Piperidine 



CH 3 CH 3 I 



Methylpiperidine Methylpiperidine 



methiodide 



CH, 



CH 

 CH, 



CH, 

 CH, 



CH, 



CH ,ACH, 



CH S 



CH, 

 CH. 2 



/ I \ 

 CH 3 CH 3 OH 



Methylpiperidine 

 methohydroxide 



N 



CH, 



CH 



CH 2 CH 2 



CH 



+ 



+ H„0 



CH, CH 3 CH 3 CH :i 



N 



N " 



/ 



CH 3 CH 3 CH 3 CH 3 CH 3 OH 



Dimethylpiperidine Dimethyl pi peridyl 



methohydroxide 



Piperylene 



Trimethylamine 



By applying a perfectly analogous series of reactions to 



codeine, the ring which contains the nitrogen has been opened 



and the base thereby resolved into nitrogen-free products and 



amines, thus : 



/CH 3 

 CH P(C 16 H u O):N^CH 3 -> 



Codeine Codeine methiodide 



HO\ /CH 3 



CH 3 0/ \OH 



Codeine methohydroxide 



°>(C* H "C.):N.CH 3 -> 



CH 3 



