Benzopyrone derivatives exhibiting anti-allergic activity

摘要

Benzopyrones of the formula <IMAGE> wherein R1 is a hydrogen or halogen atom or a hydroxyl, lower alkyl, alkoxy, alkylthio or trifluoromethyl radical, R2, R3, R4 and R5 each independently is hydrogen, a halogen atom, a hydroxyl radical, a lower alkyl or lower alkoxy radical, or a lower alkyl or lower alkoxy radical substituted by at least one of hydroxyl, halogen, mesyloxy or tosyloxy or by an oxirane, dioxane or dioxolane ring, A is a lower alkylene radical, and N IS 0, 1 OR 2, AND SALTS THEREOF EXHIBIT ANTI-ALLERGIC ACTIVITY.