In this study heterocyclic compounds were prepared from thioxanthone derivatives and determined their structure by measuring melting point (M.P) and infrared spectrum (FTR) and 1HNMR for each one. These derivatives used for testing antibacterial activity Streptococcus mutans, Staphylococcus saprophyticus, Enterococcus faecalis (Gram positive bacteria) Haemophilus influenzae (Gram negative bacteria). Prepared compounds I,II,III,IIV showed clear antibacterial activity against all tested bacteria either as solutions or powder. Solutions with DMSO have antibacterial activity greater than those with distilled. Compound I showed greater antibacterial activity than other compounds. On the other hand, Gram-positive bacteria showed higher sensitivity than Gram-negative ones to all solutions. The results of thermal analysis of the prepared derivatives showed stability at high temperatures (DSC and TG curves).
Key words: Thioxanthone, Schiff bases, antibacterial activity , imidazolidin-4-one , Oxazepine .