Synthesis of chloro and bromo substituted 5-(indan-1'-yl)tetrazoles and 5-(indan-1'-yl)methyltetrazoles as possible analgesic agents.

Chloro and bromo substututed indanyl tetrazoles (compounds 5a, b) and indanyl methyltetrazoles (compounds 5c, 5d) have been synthesized from their respective acids through amide and nitrile routes, and characterized. The title compounds (5a, 5b, 5c and 5d) were subjected for their analgesic activity in the acetic acid induced writhing test on albino mice. The significant (p < 0.001) analgesic activity, exhibited by the compound 5b at a dose of 50 mg/kg body weight, was comparable to that of phenylbutazone and indometacin at a dose of 100 and 50 mg/kg body weight respectively. The effect of substitution at the benzenoid part of the indan nucleus and chain lenght on analgesic activity was in the following order: bromine > chlorine and tetrazole > methyltetrazole.