(1H,3H,5H)-(1)-Benzopyrano-(2,3-d)-pyrimidine-4-one-2-thiones and their use as anti-allergy agents

摘要

This invention relates to (1H,3H,5H)-(1)-benzopyrano-(2,3-d)-pyrimidine-4-one-2-thiones, to pharmaceutically acceptable salts thereof, to the methods for their preparation and to their use as agents in the prophylactic treatment of allergic conditions such as asthma, allergic rhinitis, urticaria and ulcerative colitis.