Eschenmoser Coupling Reaction and Reactivity of Hydrazinecarbo­thioamides in the Synthesis of Benzindazole and Naphthothiazole Derivatives

N-Unsubstituted and N -substituted 2-phenylhydrazinecarbothioamides react with 2,3-dichloro-1,4-naphthoquinone to give a series of unprecedented 3-amino- and 3-(alkylamino)-1-phenyl-1 H -benzo[ f ]indazole-4,9-diones in good yields. On the other hand, the reaction of N -substituted 2-tosylhydrazinecarbothioamides with 2,3-dichloro-1,4-naphthoquinone afforded ( Z )- N -[3-(tosylamino)-4,9-dioxo-4,9-dihydronaphtho[2,3- d ]thiazol-2(3 H )-ylidene]-substituted aminium chlorides and ( Z )- N -[(2-substituted imino)-4,9-dioxo-4,9-dihydronaphtho[2,3- d ]thiazol-3(2 H )-yl]-4-toluenesulfonamide hydrates.