| Abstrakt: |
A substituted nicotininc 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-[b]-l,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[b]-l,8-naphthyrid-10-one derivatives, while 4,6-dimethyl-2-arylaminonicotinonitriles are converted primarily to 10-aminobenzo[b]-l,8-naphthyridines. |
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