Abstract
The reaction of the 2-(4-oxo-4,5-dihydrothiazol-2-yl) acetonitrile (1) with salicylaldehyde (2) in 1,4-dioxane containing a catalytic amount of piperidine gave the coumarin derivative 3. The latter reacted with different reagents to give pyrano[ 4,5-b] thiazole, pyrido[4,5-b] thiazole and thieno[5,4-b] thiazole dereivatives. The anti-inflammatory and anti-ulcer activities of the newly synthesized products were evaluated and the results showed that compounds 7a, 8a, 10b, 13b, 15b, 18a, 19b, 19c, and 19d showed higher activity compared to the rest of the compounds. In addition to this, toxicity of such active compounds was studied against shrimp larvae where compounds 10b, 18a, 19c and 19d showed to be non-toxic against the tested organisms.