Reactions of hydrazonoyl halides 43 : Synthesis of some new 2,3‐dihydro‐1,3,4‐thiadiazoles,pyrazoles, pyrazolo[3,4‐d]‐pyridazines,thieno[2,3‐b]pyridines,pyrimidino[4′,5′:4,5]thieno[2,3‐b]‐pyridines and pyrrolo[3,4‐d]pyrazoles

2,3‐Dihydro‐1,3,4‐thiadiazoles, pyrazoles, pyrazolo3,4‐d]pyridazines, thieno2,3‐b]pyridines, pyrim‐idino4′,5′:4,5]thieno2,3‐b]pyridines and pyrrolo3,4‐d]pyrazoles were obtained in a good yields by treatment of hydrazonoyl halides with each of alkyl carbodithioates, 3‐(dimethylamino)‐1‐naphtho1,2‐d]furan‐2‐ylprop‐2‐en‐1‐one and N‐arylmalemides.