I. Studies on the chinoline series

Abstract

In the first part of this paper which appeared in the “Proceedings” of the Society for 1877, it was shown that the leucoline series of bases occurring in coal tar were really aromatic derivatives, as on oxidation an acid could be obtained which readily decomposed on distilling with an alkali, giving aniline. The acid, which was named leucolinic acid, had the composition C 9 H 9 NO 3 , and may be regarded as a higher homologue of isatic acid, C 8 H 7 NO 3 , which is one of the characteristic indigo derivatives. The conclusions of this paper have been confirmed by the synthesis of chinoline by Baeyer from the hydro-carbostyril, and by Koenigs from allylaniline, the latter reaction being similar in principle to the synthesis of pyrrol, described in my former paper, by passing ammonia and a mixture of monobromethylene and acetylene through a red hot tube.