Compounds having acenaphthene and indan as their parent nuclei were synthesized for antiinflammatory testing. Compounds which showed activity were 1-phenyl-5- acenaphthenylacetic acid and its a-methyl derivative (carrageenan rat paw edema) and the same a-methylacenaphthenylacetic acid and 2-(4-chlorobenzylidene)-3-oxo-5-indanacetic acid and its a-methyl derivative (rat adjuvant arthritis). None of the compounds was more ...