| abstract |
There are disclosed compounds of formula (I) wherein R?1 is lower alkyl, lower alkoxycarbonyl lower alkyl, aralkoxycarbonyl, aralkoxycarbonyl lower alkyl or indol-2-yl lower alkyl; R?2 is hydrogen, lower alkyl, phenyl lower alkylcarbonyl or biphenylyl lower alkylcarbonyl; or R?1 and R?2 taken together form a 5- or 6-membered saturated heteroyclic ring; R?3 is hydrogen or lower alkyl; R?4 is alkyl of 10 - 20 carbon atoms, cycloalkyl of 10 - 20 carbon atoms or phenylalkyl of 10 - 16 carbon atoms; or R?3 and R?4 taken together are decahydroisoquinolin-2-yl, 3,5-dimethylpiperazin-1-yl or 3,3,5-trimethylhexahydroazepin-1-yl; or a pharmaceutically acceptable salt thereof, and their use in the prevention and/or treatment of conditions such as allergic rhinitis, allergic bronchial asthma and other naso-bronchial obstructive air-passageway conditions, other immediate hypersensitivity reactions such as allergic conjunctivitis and various inflammatory conditions. |