Synthesis and antimicrobial evaluation of carbonyl isothiocyanate derivatives spiro [indoline-3,2’-[1,3,5]oxadiazin]-2-one

The synthesis of 6'-phenyl-3'-(thiazol-2-yl)-4'-thioxo-3',4'-dihydrospiro[Indoline-3,2'-[1,3,5]oxadiazin]-2-one 5a-h is carried out through a three step pathway starting from acid catalyzed condensation of 2-amino thiazole 1 with indoline-2,3-dione 2 which is also called isatin yielding 3-(thiazol-2-ylimino)indolin-2-one 3 which on reaction with 4-(substituted)-cyclohexa-1,5-diene carbonyl isothiocyanate 4a-h in the presence of anhydrous ZnCl2 gives targeted compounds. All synthesized compounds have been characterized by 1H-NMR, 13C-NMR, IR and elemental analysis. Final compounds have been screened for antimicrobial activity.