Reactions of 6-Methyl- and 4,6-Dimethyl-2-arylaminonicotinonitriles with Acids

Article abstract of DOI:10.1007/BF00526089

A substituted nicotinic acid is formed when 6-methyl-2-anilinonicotinonitrile is refluxed with concentrated hydrochloric acid, whereas 4,6-dimethyl-2-anilinonicotinonitrile is not hydrolyzed under these and more severe conditions because of steric hindrance.Both of these nitriles undergo cyclization to 10-aminobenzo-1,8-naphthyridine derivatives under the influence of concentrated sulfuric acid.When 6-methyl-2-arylaminonicotinonitriles are heated in polyphosphoric acid (PPA), they are converted to 2-arylaminonicotinic acid amides and, in part, to benzo-1,8-naphthyrid-10-one derivatives, while 4,6-dimethyl-2-arylaminonicotinonitriles are converted primarily to 10-aminobenzo-1,8-naphthyridines.