130 PYRIUINE BASES. 



ammonia is heated to 90-100. Amorphous brown 

 mass, very much like acrolein-ammonia. Combines, 

 like the latter, with acids, yielding amorphous salts ; 

 and is resolved by heat into water and collidine. 



Pyridine bases, CME 2n - 5 T. &quot;When acrolein-ammo 

 nia and crotonal-ammonia are heated, there result liquid 

 bases, picoline and collidine, which belong to an homo 

 logous series, the single members of which are formed 

 by the dry distillation of anthracite coal, peat, and 

 particularly of bones. They are extracted from the 

 distillation-products (coal-tar, bone-oil) by treating 

 with dilute sulphuric acid ; set free again by means of 

 alkalies; and separated from each other by means of 

 fractional distillation. 



1. Pyridine, C 5 H 5 ]Sr. Colorless liquid, of a penetrat 

 ing odor. Boiling point, 116.7 ; specific gravity, 0.986 

 at 0. Soluble in water. Strong base. The hydro- 

 chlorate C 5 IKN&quot;.HC1 is deliquescent, and gives with pla 

 tinum chloride a yellow double salt (C 5 H 5 KHCl) 2 PtCl 4 , 

 which is difficultly soluble in water. 



In the presence of metallic sodium, pyridine is 

 changed, gradually at the ordinary temperature, more 

 rapidly when heated, into a polymeric base, dipyridine 

 C 10 H 10 N 2 , which crystallizes in colorless needles, fuses 

 at 108, and sublimes without decomposition. 



2. Picoline, C 6 H 7 N. Is formed by the distillation- 

 of acrolein-ammonia and also when tribromhydrine is 

 heated for several days with alcoholic ammonia to 

 250. Colorless liquid, mixes with water ; specific 

 gravity, 0.96 ; boiling point, 135. Strong base. Is 

 converted into a polymeric base by sodium, the same 

 as pyridine. 



3. Lutidine, C 7 HXN&quot;. Colorless liquid ; specific 

 gravity, 0.946 ; boiling point, 155.5. More easily 

 soluble in cold water than in hot. 



