Quinolizinone compound and use thereof as HIV integrase inhibitor

A quinolizinone compound represented by the following formula [II] or a pharmaceutically acceptable salt thereof:

• wherein
• R6 is a group selected from group A below,
• wherein the group A is a group consisting of a cyano group, a nitro group, a halogen atom, a C1-4 alkyl group, a halo C1-4 alkyl group, a halo C1-4 alkyloxy group, —ORa1, —SRa1, —NRa1Ra2, —CONRa1Ra2, —SO2NRa1Ra2, —CORa3, —NRa2CORa3, —SO2Ra3, —NRa1SO2Ra3, —COORa1, and —NRa2COORa3,
• wherein Ra1 and Ra2 are the same or different and each is a hydrogen atom, or a C1-4 alkyl group, and Ra3 is a C1-4 alkyl group;
• R4 and R5 are the same or different and each is a group selected from a hydrogen atom and group A above, or
• R4 and R5 may form a fused ring together with a benzene ring they substitute;
• m is 0 or an integer of 1 to 3, and when m is 2 or 3, then R6 of each may be the same or different;
• R1 is a hydrogen atom, a group selected from group B below or a C1-10 alkyl group optionally substituted by 1 to 3 substituents selected from a halogen atom and group B below,
• wherein the group B is a group consisting of a C3-10 carbon ring group optionally substituted by 1 to 5 substituents selected from group A above,
• a heterocyclic group optionally substituted by 1 to 5 substituents selected from group A above,
• wherein the heterocyclic group is a saturated or unsaturated ring group containing, besides carbon atom(s), at least one hetero atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom,
• a cyano group, —ORa4, —SRa4, —NRa4Ra5, —CONRa4Ra5, —SO2NRa4Ra5, —CORa6, —NRa4CORa6, —SO2Ra6, —NRa4SO2Ra6, —COORa4, —NRa5COORa6, —NRa4CO—NRa5Ra12, —NRa4CO—COORa5, —O_W—ORa5, —NRa4—W—ORa5, —NRa4—W—SO2NRa5Ra12, —NRa4CO—W—Ra5, —NRa4CO—W—NRa5, —NRa4CO—W—COORa5, and —NRa4CO—W—NRa5CORa6,
• wherein Ra4, Ra5 and Ra12 are the same or different and each is a hydrogen atom, a C1-4 alkyl group, a C3-10 carbon ring group optionally substituted by 1 to 5 substituents selected from group A above, or a heterocyclic group (the heterocyclic group is as defined above) optionally substituted by 1 to 5 substituents selected from group A above, Ra6 is a C1-4 alkyl group, a C3-10 carbon ring group optionally substituted by 1 to 5 substituents selected from group A above or a heterocyclic group (the heterocyclic group is as defined above) optionally substituted by 1 to 5 substituents selected from group A above, and W is a C1-10 alkylene group;
• R2 is a hydrogen atom or a C1-4 alkyl group;
• Z is C—R31 or a nitrogen atom,
• wherein R31 is a hydrogen atom, a cyano group, a hydroxy group, an amino group, a nitro group, a halogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkylsulfanyl group, a halo C1-4 alkyl group, or a halo C1-4 alkyloxy group;
• X is C—R32 or a nitrogen atom;
• and
• Y is C—R33 or a nitrogen atom,
• wherein R32 and R33 are the same or different and each is a hydrogen atom, a cyano group, a nitro group, a halogen atom,
• a C3-10 carbon ring group optionally substituted by 1 to 5 substituents selected from group A above,
• a heterocyclic group (the heterocyclic group is as defined above) optionally substituted by 1 to 5 substituents selected from group A above,
• a C1-10 alkyl group optionally substituted by 1 to 3 substituents selected from a halogen atom and group B above,
• —ORa7, —SRa7, —NRa7Ra8, —NRa7CORa9, —COORa10 or —N═CH—NRa10Ra11,
• wherein Ra7 and Ra8 are the same or different and each is a hydrogen atom, a group selected from group B above, or a C1-10 alkyl group optionally substituted by 1 to 3 substituents selected from a halogen atom and group B above, Ra9 is a C1-4 alkyl group, and Ra10 and Ra11 are the same or different and each is a hydrogen atom or a C1-4 alkyl group.