270 Dr. W. Ramsay on Picoline and its Derivatives. 



Chapman and Smith (Ann. Chem. Pharm. Suppl. vi. p. 329) 

 dehydrated ainyl nitrate by means of phosphoric anhydride, 

 and thus succeeded in obtaining a small quantity of pyridine. 



C 5 H n N0 3 =C 5 H 5 N + 3H 2 0. 



Aniyl nitrate. Picoline. 



Glaus found picoline among the decomposition-products of 

 the distillation of acrolein ammonia, and Bayer (Ann. Chem. 

 Pharm. vol. civ. p. 281) prepared collidine by an analogous 

 process, viz. by submitting aldehyde ammonia to dry distil- 

 lation. The reactions are these : — 



C 6 H 9 NO - H 2 = C 6 H 7 K 



Acrolein ammonia. Picoline. 



2C 2 H 4 = C 4 H 6 + H 2 0. 



Acetic aldehyde. Crotonic 



aldehyde. 



C 8 H 13 NO - H 2 = C 8 H n K 



Crotonic aldehyde Collidine. 



ammonia. 



Bayer also prepared picoline from tribromallyl, C 3 H 5 Br 3 , 

 by heating it with alcoholic ammonia ; the resulting tribrom- 

 allylamine is decomposed by further heat : — 



2 C 3 H 5 Br 3 + NH 3 = (C 3 H 4 Br) 2 NH + 4 HBr, 

 and 



(0 3 H 4 Br) 2 NH = C 6 H 7 N + 2 HBr. 



Huber (Ann. Chem. Pharm. vol. cxli. p. 277) obtained pyri- 

 denedicarbonic acid from nicotine by oxidation with chromic 

 acid ; and from the pyridenedicarbonic acid pyridine was 

 prepared. Weidel, on repeating Huber's experiment by drop- 

 ping nicotine into fuming nitric acid, evaporation, and forma- 

 tion of the silver salt, which was then decomposed by sulphu- 

 retted hydrogen, obtained an acid of the formula C 10 H 8 ~N 2 3 , 

 which yielded pyridine on distillation with lime. The author 

 draws attention to the fact that his analyses, with exception of 

 the nitrogen-determination, gives results which agree equally 

 well with the formula C G H 4 N . CO OH ; the analyses of the 

 compounds which the acid formed with hydrochloric, hydro- 

 bromic, nitric acid &c. also gave numbers agreeing with that 

 formula. The author states that bromine acts on the acid 

 thus: 



do H 8 N 2 3 + H 2 + Br = C 5 H 5 NHBr + 3 CHBr 3 

 + 2C0 2 + N+HBr. 



Weidel oxidized nicotine with chromic anhydride ; pyri- 

 denedicarbonic acid was not formed, but nicotinic acid ; he 



