| abstract |
The present invention relates to new 1,8-naphthyridine derivatives, to antitumor agents containing them as an effective agent, and to processes for the preparation of said 1,8-naphthyridine derivatives, represented by formula (I), where R1 is a carboxyl group or a group convertible to a carboxyl group, and Y is a removable group or a group represented by formula (Y) where R2 is a hydrogen atom or a lower alkyl group, R3 is a dehydrogenic atom or a convertible group at a hydrogen atom, and R4 is a lower alkoxy group or a lower alkyl group. |