Pyridine derivatives

摘要

There is provided a pyridine derivative represented by the formula (I) <IMAGE> (I) wherein each of R1 and R2 independently represents hydrogen or lower alkyl and each of R3 and R4 independently represents hydrogen, lower alkyl, alicyclic alkyl, substituted or unsubstituted polycyclic alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclic group, or R3 and R4 are combined with nitrogen atom adjacent thereto to form a substituted or unsubstituted alicyclic heterocyclic group, or pharmaceutically acceptable salt thereof. The pyridine derivative exhibits bone resorption inhibiting effect and is useful as a medicament for treating osteoporosis.