1880.] 



Studies on the Chinoline Series. 



The crude acid separated from the potash salt or the insoluble lead 

 salt always contains a considerable quantity of a syrupy acid, which 

 does not crystallise unless it is boiled with water for some days. It is 

 possible this substance may be the acid derived from one of the 

 isomeric bases, and that it is slowly changed into the crystalline 

 modification. The crystalline leucolinic acid treated with glycerine 

 gives a substance having the characteristic reactions of indol, but the 

 amount obtained is always small; many attempts made to increase 

 the yield of this body have not been successful. If fused chloride of 

 zinc be employed instead of glycerine, the distillate is hydro chlorate of 

 aniline, without any of the indol substance. Similarly, a solution of 

 the potash salt of the acid, heated to 200° C, gave only aniline, 

 carbonic and acetic acids. On heating the acid with zinc-dust, 

 chinoline was not reproduced, as the product was a crystalline sub- 

 stance which has not been examined. 



The decompositions of leucolinic and chinolinic acids point to their 

 being amido-phenylpyruvic acids, and their general relations to nearly 

 allied substances are shown in the following formulas : — 



C 6 H 5 C 6 EySTH 3 C 6 H 4 ira C 6 H 4 N C 6 H 4 NH, 



CH CH CH CH CH 



CH CH CH CH CO~ 



COoH COoH CO CH COoH 



Cinnamic Amido- Cavbostyril. Chinoline. Leucolinic and 



Acid. cinnamic. Chinolinic Acids. 



An acid of this character ought to be hydrogenised readily, pro- 

 ducing the amido-phenylactic acid which has the same composition 

 and a close relationship to the substance tyrosine, differing only in 

 the amido-group being in this case attached to the phenyl residue 

 instead of to the pyruvic ; such isomeric tyrosines are produced by 

 treating leucolinic and chinolinic acids with sodium amalgam. Both 

 products react with the mixed mercurous and mercuric nitrates, 

 giving a red colour, somewhat resembling the well-known tyrosine 

 reaction, the difference between them and ordinary tyrosine being 

 that, on fusion with an alkali, both yield aniline, whereas ammonia 

 and paroxy-benzoic acid are the products obtained from, the normal 

 substance. 



