Abstract: Novel phenylalkanoic compounds of the formula I ##STR1## wherein R.sub.1 and R.sub.2 independently from each other represent hydrogen or alkyl with 1 to 8 carbon atoms, salts of such compounds and salts thereof, therapeutic uses of the phenylalkanoic compounds, or of the pharmacologically safe salts thereof for treating inflammatory diseases, tussive states, pain symptoms and pyretic diseases and pharmaceutical composition containing the phenylalkanoic compounds or the pharmacologically safe salts together with a carrier and an optional adjuvant or additive.

Abstract: A process for manufacturing pure diosmin suitable as a therapeutic agent comprising acetylating hesperidin, observing by means of ultraviolet absorption the progress of the acetylation reaction and continuing such reaction until there disappears the band initially occurring at a wave length in the range of 264 to 280 nm and there appears in place thereof a new maximum at a wave length of about 330 nm. Thereafter the acetylation product is brominated, the obtained bromination product hydrolyzed and the obtained product after precipitation isolated, in order to obtain diosmin having a bromine content less than 0.1%.