This invention relates to chromone derivatives having the formula and the formula wherein R' is selected from the group consisting of methylene, ethylene, isopropylene and propylene and physiologically acceptable salts, lower alkyl esters and amides with lower alkyl amines of each of the compounds of said two structural formulas wherein said lower alkyl groups have one to four carbon atoms. Said derivatives possess activity as inhibitors of the antigen-antibody reaction.
This application is a divisional of application Ser. No. 588,322, filed on Oct. 21, 1966 and now U.S. Pat. No. 3,551,572, which in turn is a continuation-in-part of application Ser. No. 266,036, filed Mar. 18, 1963 and now U.S. Pat. No. 3,291,811.
