PURPOSE: To provide the new chromone derivative useful for treating allergic diseases by internal use, which has pronounced suppressing action to antigen- antibody reaction caused by controlling action to liberation of the chemical mediator and is effectively used by the oral administration.
CONSTITUTION: The chromone derivative is expressed by formula I, i.e., 6,7- methylenedioxychromone-2-tetrazole, is obtained by condensing 2-hydroxy-4,5- methylenedioxyacetophenone of formula II with sodium ethoxide in diethylcitrate to obtain ethyl ester of formula III, then reacting the ester with ammonia to obtain an amide of formula IV, further dehydrating the amide to obtain a nitrile of formula V, and finally reacting the nitrile with hydrogen azide or its salt. The compound of formula I has strong suppressing action to passive cutaneous anaphylactic reaction.
RO GIYOKUKA
SHII HOUTOKU
YANA GIYOUTEN
TAISHO PHARMACEUTICAL CO LTD