CYTISINE. 
§ 479-] 
407 
It is capable of sublimation in a current of hydrogen at 154-5° ; the 
sublimate is in the form of very long needles and small leaflets ; at 
higher temperatures it melts to a yellow oily fluid, again becoming 
crystalline on cooling. Cytisine is a strong base ; it precipitates the 
earths and oxides of the heavy metals from solutions of the chlorides, 
and, even in the cold, expels ammonia from its combinations. 
Cytisine forms numerous crystalline salts, among which may 
be mentioned two platinochlorides, C^H^N^H^PtClg-f 2JH 2 0 and 
(C 11 H 14 N 2 0) 2 H 2 PtCl 6 , crystallising in golden-yellow needles, which are 
tolerably soluble in water ; and the aurochloride, C n H ]4 N 2 OHAuCl 4 , 
crystallising in short, red-brown, hook-shaped needles ; m.p. 212° to 
213°, without evolution of gas. 
Cytisine forms at ordinary temperatures a condensation product 
with formaldehyde, viz. methylene dicytisine, CH 2 (C n H 13 ON 2 ) 2 . This 
may be crystallised from a solution in toluene ; the m.p. of the crystals 
is 212° (Freund and Friedmann, Ber., 1901). 
§ 479. Reactions of Cytisine. —Concentrated sulphuric acid dis¬ 
solves cytisine without colour ; if to the solution is added a drop of 
nitric acid, it becomes orange-yellow, and on addition of a crystal of 
potassic bichromate, first yellow, then dirty brown, and lastly green. 
Concentrated nitric acid dissolves the base in the cold without colour, 
but, on warming, it becomes orange-yellow. Picric, tannic, and phospho- 
molybdic acids, potassic, mercuric, and potass-cadmium iodides, and 
iodine with potassic iodide, all give precipitates. Neither potassic 
bichromate nor mercuric chloride precipitates cytisine, even though 
the solution* be concentrated. The best single test appears to be the 
reaction discovered by Magelhaes ; this consists in adding thymol 
to a solution of cytisine in concentrated sulphuric acid, when a yellow 
colour, finally passing into an intense red, is produced. The reaction 
with formalin (formaldehyde) may be useful for purposes of identification. 
V. d. Moer’s reaction .—Cytisine or a cytisine salt, treated with a solu¬ 
tion of a ferrous salt, produces a red colour. This vanishes if a drop of 
hydrogen peroxide is added, but on warming on a water-bath there is a 
blue colour. Anagyrin, C ]5 H 22 N 2 0, an alkaloid occurring with cytisine 
in the seeds of Anagyris fetida, gives the same play of colours, but 
mercuric chloride gives a crystalline precipitate with anagyrin, no 
precipitate with cytisine. 
Cytisine may be extracted from an acid solution by chloroform. On 
evaporation of the CHC1 3 , if a solution of potassium permanganate in 
strong H 2 S0 4 is added, and a violet colour is produced, while the same 
residue gives no colour either with Erdmann’s reagent or with con¬ 
centrated sulphuric acid, then one of the following four substances may 
be suspected : cytisine, theobromin, aspidospermin, cinchonine. 
Cytisine warmed with double its bulk of concentrated HN0 3 on a 
