Anthranilic acid was allowed to react with aroyl chlorides in pyridine to give 2-aryl/heteroaryl -3,1-benzoxazin -4-ones (1a-h). These 1a-h were allowed to react with hydrazine hydrochloride in presence of ethanol to result 3-amino-2 -aryl/heteroaryl-4(3H)-quinazolinones(2a-h). The 2a-h reacted with Furfuraldehyde and yielded 3-Furylidine amino-2-aryl/heteroaryl-4(3H)-quinazolinones (3a-h). Now 3a-h were treated with mercaptoacetic acid in presence of benzene to give 2-Furyl-3-(4-oxo-thiazolidin-3-yl)-2-aryl/heteroaryl-4(3H)-quinazolinones(4a-h). A representative number of synthesised compounds were evaluated for their antimicrobial activities.