Some reactions with 6-benzoyl-3-amino-2-imino-2,3-dihydrothiazolo[4,5-b]quinoxaline: Synthesis of (1,2,4) triazolo[3 ',2 ': 2,3]thiazolo[4,5-b]quinoxaline and (1,3,4)thiadiazino[5,6-b]quinoxaline derivatives

Condensation of 6-benzoyl-3-amino-2-imino-2,3-dihydrothiazolo[4,5-b]quinoxa line (IV) with aldehydes, formic acid and acetyl chloride yielded the corre sponding Schiff bases (VI), N-formyl (VIII) and triacetyl (IX) derivatives, respectively. While, interaction of (IV) with benzoyl chloride and ethyl c yanoacetate produced the (1,2,4) triazolo[3',2':3.2] thiazolo[4,5-b]quinoxa line derivatives CX) and (XI), respectively. Also, interaction of (IV with carbon disulphide caused ring expansion to give (1,3,4) thiadiazino[5,6-b]q uinoxaline (XII) and (XV) was also prepared in one pot reaction on condensa tion of 6-benzoyl-2,3-dichloroquinoxaline with thiocarbohydrazide.