Synthesis of some new formazanyl-thiazolyl-indoles and formazanyl-oxazolyl-indoles as inflammation inhibitors

Various 3-(2-arylideneaminothiazol-4-yl)indoles 3a-e and 3-(2-arylideneamin ooxazol-4-yl)indoles 3a'-e' on diazotisation with aniline afford 3-[2-(1'-p henyl-3'-substituted-aryl-formazan-4'-yl)thiazol-4-yl] indoles 4a-e and 3-[ 2-(1'-substituted-phenyl-'3 -substituted aryl-formazan-4'-yl)oxazol-4-yl]in doles 4a'-e' respectively. All the compounds have shown interesting antiinf lammatory activity in carrageenan induced oedema in rats at 50 mg/kg p.o. T he most active compound in the series is 3-[2-(o-methoxybenzylidene)aminoth iazol-4-yl]indole which has shown higher antiinflammatory activity and lowe r ulcerogenic property than phenylbutazone.