Nucleophilic reactions of 1-substituted-2,5-dithiobiureas with chlorinated benzo- and naphthoquinones as well as (1,3-dioxo-2,3-dihydro-1(H)-inden-2-ylidene)propanedinitrile

Abstract

Nucleophilic attack by 1-substituted-2,5-dithiobiureas on C-2, C-3 of 2,3,5,6-tetrachloro-1,4-benzoquinone and 2,3-dichloro-1,4-naphthoquinone initiates the formation of benzo-and naphthoimidazothiadiazolediones. On the other hand, 1-substituted-2,5-dithiobiureas attack 2,3,5,6-tetrachloro-1,4-benzoquinone and 2,3-dichloro-1,4-naphthoquinone at (C-1, C-2, C-4 and C-5) as well as (C-1, C-2, C-3 and C-4), respectively to form benzo-and naphthoimidazothiadiazoles. The reaction of (1,3-dioxo-2,3-dihydro-1(H)-indene-2-ylidene)-propanedinitrile with 1-substituted-2,5-dithiobiureas forming the derivatives of (oxoindenothiazinylidene)hydrazinecarbothioamide as well as (oxoindenopyrrolylidene)hydrazinecarbothioamides. A rationale for the conversions observed is presented.