Condensed 1,2-indene dihydride and its salt for medicine its preparation method and application

A fused indan derivative represented by general formula (1), a pharmaceutically acceptable salt thereof, and an antitumor drug, wherein ring A represents an optionally substituted benzene or naphtalene ring, or a benzene ring having a lower alkylenedioxy group; ring B represents a benzene ring which may be substituted or has a lower alkylenedioxy group; Y represents -N=CR- or -CR=N-; R represents -NR1R2, -OR3 or an optionally substituted nitrogenous heterocyclic group; R1 and R2 are the same or different from each other and each represents hydrogen, phenyl, an optionally substituted nitrogenous heterocyclic group, or a lower alkyl group which may be substituted by at least one substituent selected from the group consisting of optionally substituted amino, lower alkoxy, phenyl, a nitrogenous heterocyclic group, an amine oxide group substituted by lower alkyl, and hydroxy; and R3 represents lower alkyl which may be substituted by substituted amino, provided the case where R represents an optionally substituted nitrogenous heterocyclic group and rings A and B represent each an unsubstituted benzene ring, is excluded.