Synthesis and Characterization of Some New Heterocyclic Compounds Derived from Thiosemicarbazide (A Response Surface Methodology Approach)

In this work new thiosemicarbazide derivatives were synthesized to obtain the intermediate of thiosemcarbazone compounds (1-5) by thiosemicarbazide reaction with several aromatic aldehydes, following treatment of compounds (1-5) with 2-chloroethanoic acid with sodium acetate, a series of compounds (6-8) was prepared. There were 1,3-oxazepine-4,7-dione derivatives compounds (9,10) with phthalic anhydride. By heating thiosemicarbazide with carbon disulfide and anhydrous sodium carbonate in absolute ethanol, 5-amino-1,3,4-thiadiazole-5-thiol compound (11) was prepared. The azomethines synthesized by reaction of compound (11) with aromatic aldehyde compounds (12-14), then processed to obtain mercaptoacetic acid as compounds (15-17). The compound (18) was made with ethylchloroacetate from the cyclization thiosemcarbazone compound (2) in the presence of fused sodium acetate. The reaction of compound (11) with chloroacetylchloride produced compound (19) then treated with urea to obtained compound (20) followed by 4- phenyl phenacyl bromide to prepare compound (21). The characterization outcomes for the prepared compounds verified their chemical structures using IR spectroscopy, NMR, and melting points.