NAPHTHYRIDINE DERIVATIVES

摘要

Naphthyridine derivatives represented by general formula (1) wherein A represents lower alkylene; R1 represents hydrogen or an electron pair "-"; R2 represents optionally substituted phenyl; R3 represents (a) (wherein R4 and R5 each represents lower alkyl, etc.) when R1 is an electron pair "-", or represents -S-R6 (wherein R6 represents lower alkyl, etc.) when R1 is hydrogen; and R7 represents hydrogen or lower alkyl!; and an analgetic preparation containing any of the derivatives as the active ingredient.