450 SINAPINE. 



in cold concentrated sulphuric acid, giving a dark red 

 colored solution. Very weak base. 



Decompositions. Heated with soda-lime, it yields 

 piperidine ; by boiling with an alcoholic solution of po- 

 tassa, it is resolved into piperidine and piperic acid 

 (p. 383), one molecule of water being taken up. 



Piperidine, C 5 H U N = C 5 H 10 .KEL Colorless fluid ; 

 mixes with water and alcohol ; boils at 106 ; strongly 

 alkaline ; gives well crystallizing salts with acids. 



It conducts itself towards the iodides of the alco- 

 holic radicles exactly like couine. 



Methylpiperidine, C 5 H 10 .KCH 3 ,and Ethylpiperi- 

 dine, C 5 H 10 .KC 2 H 5 , are colorless fluids, boiling at 118 

 and 128, respectively. Piperine is decomposed by ben- 

 zoyl chloride, forming piperidine hydrochlorate and 

 crystalline benzoylpiperidine, C 5 H 10 .N.C 7 H 5 0. Other acid 

 chlorides conduct themselves in an analogous manner. 

 Piperine is a compound of this kind. 



12. Sinapine. 



Occurrence. In the seeds of Sinapis alba as sinapine 

 sulphocyanate. 



Preparation. Yellow mustard is freed of most of its 

 fatty oil by pressure ; first exhausted with cold alcohol, 

 and then with hot 85 per cent, alcohol ; most of the 

 alcohol distilled off; and the lighter layer of liquid, 

 which separates on cooling, removed. Sinapine sul- 

 phocyanate crystallizes from the residue, which is 

 purified by pressing and recrystallizing from alcohol. 



The free base cannot be prepared on account of the 

 ease with which it undergoes decomposition. 



Sinapine sulphocyanate, C 16 H 23 is T 5 .HCNS. 

 Colorless very voluminous crystalline mass, consisting 

 of fine needles, difficultly soluble in cold water and 

 alcohol, easily in hot ; fuses at 130. 



Sinapine sulphate, C 16 H 23 K0 5 .H 2 S0 4 + 2H 2 0, crystal- 

 lizes from a hot alcoholic solution of the sulphocyanate 



