Synthesis and Mass Spectra of Thiazole and Thiohydantoin Derivatives

5-Phenyl-2-[2-(3-phenylprop-2-en-1-ylidene)hydrazinyl]-1,3-thiazole (2) and 3-[(3-phenylprop-2-en-1-ylidene)amino]-2-sulfanylideneimidazolidin-4-one (4) were synthesized by the reaction of cinnamaldehyde and thiosemicarbazide to give substituted thiosemicarbazone 1, followed by cyclization with phenacyl bromide or ethyl chloroacetate, respectively, in the presence of sodium acetate. Treatment of 2 and 4 with acetic anhydride gave the corresponding N-acetyl derivatives 3 and 5, and the condensation of 4 with 4-florobenzalde-hyde afforded 5-(4-fluorobenzylidene)-3-[(3-phenylprop-2-en-1-ylidene)amino]-2-sulfanylideneimidazolidin-4-one (6) which was acetylated with acetic anhydride to obtain N-acetyl derivative 7. Mass spectral fragmentation patterns of some of the synthesized compounds was studied to elucidate their structure.