EP0848000A1 — Pharmaceutical pyridine derivatives, processes for preparing the same and intermediates therefor

USPTO Abstract

A pyridine derivative of the formula (I): wherein A is group of the following formulae: R 1 and R 2 are each H, or protected or unprotected OH, R 31 , R 41 and R 42 are protected or unprotected hydroxymethyl, R 32 is H, lower alkyl, or protected or unprotected hydroxymethyl, R 33 is substituted or unsubstituted lower alkyl, and the dotted line means the presence or absence of a double bond' R 5 and R 6 are H, or protected or unprotected amino, or both combine together with the adjacent nitrogen to form substituted or unsubstituted heterocycle, or a pharmaceutically acceptable salt thereof, show excellent bronchoconstriction inhibitory activity and/or anti-inflammatory activity of airways, and are , useful in the prophylaxis or treatment of asthma.