In order to reduce
the ulcerogenic effect of ibuprofen, its carboxylic group has been converted
into 5-membered and 6-membered heterocyclic rings. Various 1,3,4-thiadaizo (y),
imidazo [2,1-b] [1,3,4] thiadiazoles (1a-d), 1,3-oxazin-2-yl (2), quinazolin-2-yl
(3, 4 and 5), hydrazine, pyrazole (6), pyrazone
(7, 8) and oxadiazole (9, 12). Derivatives of ibuprofen were prepared by
cyclization under various reaction conditions in a very good yield. The
microbial inhibitory effect of the new agents has been assessed in vitro against Gram-positive and
Gram-negative bacteria activity. Compounds (4, 5, and 8) showed the highest
antibacterial activities compared to other compounds and standard drugs.
However, compound (1b) showed the lowest antibacterial activity compared to
other compounds. All compounds have been
characterized by IR, 1H NMR and C.H.N analysis.