6-Aminoanthranilic acid

In view of the structure of lavendamycin (19), it is likely that intermediate (36) is 4-aminoanthranilic acid and both (1) and (19) contain a w-phenylenediamine (C6N2) unit. Since the carbocyclic ring of nybo-mycin (40) has been shown to be derived via a shikimate pathway (48), it, too, may now be viewed as biogenetically part of the same family. The ionophore A-16239 (41) (49) also has a m-phenylenediamine grouping, but in this case it is part of an isomeric 6-aminoanthranilic acid. 

Reductive cyclization of polychloro-o-nitrobenzaldehydes and nona-fluoro-o-nitrobenzophenone with tin and acetic acid and stannous chloride and hydrochloric acid, respectively, proceed without hydrodehalogena-tion.137,138 3-Aminoanthranil is obtained, albeit in low yield (17%), by electrolytic reduction of o-nitrobenzonitrile.139... 

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