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

Abstract

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-1H-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(3H)-ylidene]-substituted aminium chlorides and (Z)-N-[(2-substituted imino)-4,9-dioxo-4,9-dihydronaphtho[2,3-d]thiazol-3(2H)-yl]-4-toluenesulfonamide hydrates.

An Update of the Use of Thiocarbohydrazides and Thiosemicarbazides in the Preparation of Heterocycles and Their Biological Importance

“…When 2,3‐dichloro‐1,4‐naphthoquinone (DCHNQ, 84 ) was added to a stirred solution of hydrazinecarbothioamides 53a , e – h followed by refluxing with Et 3 N and triphenylphosphine (Ph 3 p) gave benzo [ f ]indazole‐4,9‐diones 85a–e in 74–87% yields (Scheme ) .…”

Eschenmoser‐Coupling Reaction Furnishes Diazenyl‐1,2,4‐triazole‐5(4H)‐thione Derivatives

“…The reaction of N ‐substituted 2‐tosylhydrazinecarbo‐thioamides via nucleophilic attack of hydrazinecarbothioamide‐SH on 2,3‐dichloro‐1,4‐naphthoquinone to give ( Z )‐ N ‐[3‐(tosylamino)‐4,9‐dioxo‐4,9‐dihydronaphtho[2,3‐ d ]thiazol‐2(3 H )‐ylidene] substituted aminium chloride and ( Z )‐ N ‐[(2‐imino)‐4,9‐dioxo‐4,9‐dihydronaphtho[2,3‐ d ]thiazol‐3(2 H )‐yl‐4‐toluenesulfonamide hydrates has been reported …”