Anti-inflammatory derivatives of indan-1-acetic acids with low gastric irritancy.

In an attempt to minimize the gastric ulcerogenicity of 6-methoxyindan-1-acetic acid and 5,6-dimethoxyindan-1-acetic acid exhibiting high anti-inflammatory activity, we synthesized their esters, amides and nitrile derivatives. It was found that the anti-inflammatory activity of ethyl esters were almost equal to those of parent acids and phenylbutazone while other derivatives were less potent. Those ethyl esters were also found to be much less ulcerogenic than phenylbutazone.