A Novel Synthesis of Heterocycles from Thiocarbohydrazides

Article abstract of DOI:10.1007/BF00807639

The reaction of thiocarbohydrazides 1a and thiocarbazones 1b with tetracyanoethylene (TCNE) afforded the thiazol, thiadiazole, thiazine, and thiadiazepine derivatives 4-7. 2-Dicyanomethyleneindane-1,3-dione(CNIND) reacted with 1a,b to give aminoindenopyrazolopyridazinone (12) and phenyl-1,2,3,4-tetraazacyclopentafluorene (13). The indazole and oxathiadiazole derivatives 17 and 19 were formed during the reaction of 1b with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDO). 6,7-Dichloro-5-phenylpyrazolophthalazinol(21) was obtained from the reaction of 1b with 2,3,5,6-tetrachloro-1,4-benzoquinone (CHL-p). The oxidative cyclization of thiodicarbazones 2a-d with the above acceptors afforded the thiadiazole and thiadiazine derivatives 8 and 10.