Newer N-substituted anthranilic acid derivatives as potent anti-inflammatory agents

The new 5-bromo-N-[2'-amino(1"-acetyl-5"substitutedaryl-2"-pyrazolin-3"-yl)-1',3',4'-oxadiazol-5'-ylmethyl]anthranilic acids 7a-7e and N-[2'-amino-(1"-acetyl-5"-substiutedaryl-2"-pyrazolin-3"-yl)-1',3',4'-thiadiazol-5'-ylmethyl]anthranilic acids 6'a-6'c have been synthesised from 5-bromo-N-(2'-aminosubstituedbenzylideneacetyl-1',3',4'-oxadiazol-5'-ylmethyl)anthranilic acids 6a-6e and N-(2'-aminosubstitutedbenzylideneacetyl-1',3',4'-thiadiazol-5'-ylmethyl)anthranilic acids 5'a-5'e, respectively. All these compounds have been screened in vivo for their anti-inflammatory and acute toxicity. Compounds 7b and 6'b were found to be potent member of this series, which showed 50.66 and 47.56%, respectively, inflammation inhibitory activity at a dose of 50 mg kg(-1) p.o., while standard drug, phenylbutazone, exhibited 45.52% anti-inflammatory activity at the same dose. However, 5-bromo-N-[2'-amino-[1"-acety1-5"-(para-methoxyphenyl)-2"-pyrazolin-3"-yl]-1',3',4'-oxidiazol-5'-ylmethyl]anthranilic acid (7b) was found to be the most active and less ulcerogcnic compound than the standard drag mid rest of the compounds of this series. The structures of these compounds have been established by IR, 1H-NMR spectroscopic data and elemental analyses.