A process for preventing the release of pharmacological mediators from an immediate hypersensitivity reaction between reaginic type antibodies and an antigen, thereby preventing the symptoms manifest in bronchial asthma, seasonal pollinosis, allergic rhinitis, urticaria, allergic conjunctivitis, food allergy, and anaphylactoid reactions of a sensitized animal, which comprises prophylactically administering to said animal an effective amount of a compound of the formula:
- ##STR12## in which B is a member selected from the group consisting of --OH, lower alkoxy, --NH.sub.2, --NHOH, cyclohexyloxy, and phenoxy.