Synthesis and Characterization of Some New Thiazine , Azetidine and Thiazolidine Compounds Containing 1,3,4- Thiadiazole Moiety an‎d Their Antibacterial Study.

2-amino-5-mercapto-1,3,4-thiadiazole [I] were prepared by the cyclization of thiosemecarbazide with carbon disulphide and anhydrous sodium carbonate in ethanol as a solvent. The reaction of compound [I] with alkyl halides yielded 2- amino-5-thioalkyl-1,3,4- thiadiazole [II] and [III] . Compound [II] and [III] were reacted with different aromatic aldehydes to yieled 2-[(substituted benzyliden ) amino] -5- thioalkyl-1,3,4- thiadiazole [IV]a-c , [V]a-d and [VI]a-d . Schiff , s bases [IV]a-c , [V]a-d and [VI]a-d were found to react with 2- mercapto benzoic acid in the triethyl amine to give 3-[ 5-( alkylthio) -1,3,4- thiadiazol-2-yl] - 2,3- dihydro- 2- (aryl) benzo [e] [1,3] thiazine -4-one [VII]a-c and [VIII]a . The Schiff , s bases reacted with chloro acetyl chloride in the triethyl amine to give 3-chloro-1-(5-alkylthio)-1,3,4- thiadiazole-2-yl)-4-(aryl)azetidine-2-one[IX]a,b , [X]c and [XI]c,d .Also Schiff , s bases reacted with 2-mercapto acetic acid in dry benzene to give 3-(5-mercapto-1,3,4-thiadiazole-2-yl)-2- (aryl)thiazolidine-4-one[XII]a,c ,[XIII]d and [XIV]c,d. The structures of the newly synthesized compounds were confirmed by physical properties and spectral (UV-Vis , FT-IR and 1H-NMR) analysis.