Abstract |
Naphthalene derivatives of the formula [I]: wherein R<SUP>l</SUP> and R<SUP>2</SUP> are the same or different and are each H, protected or unprotected OH, one of R<SUP>3</SUP> and R<SUP>4</SUP> is protected or unprotected hydroxymethyl, and the other 'is H, lower alkyl, or protected or unprotected hYdrOxYFthYI, R<SUP>5</SUP> and R<SUP>6</SUP> are the same or different and are each H, substituted or unsubstituted lower alkyl, substituted or unsubstituted phenyl or protected or unprotected , NH<SUB>2</SUB>, or both combine together with the adjacent N to form substituted or unsubstituted heterocyclic group, and pharmaceutically acceptable salts thereof, these compounds showing excellent bronchoconstriction inhibitory activity, and hence, being useful in the prophylaxis or treatment of asthma. |