Catechol derivative, pharmaceutical composition containing the same, use of the catechol derivative, and use of the pharmaceutical composition

A compound represented by general formula (I):

• or a pharmaceutically acceptable salt thereof,
• wherein
• R1 and R2 are each independently a hydrogen atom, a lower acyl group, a lower alkoxycarbonyl group, an aralkylcarbonyl group or —C(O)NR11R12, or R1 and R2 are joined together to form —C(O)— or a lower alkylene group;
• R3 is:
• a) a halo-lower alkyl group,
• b) a lower acyl group,
• c) a halo-lower alkylcarbonyl group,
• d) a cycloalkylcarbonyl group,
• e) an arylcarbonyl group, wherein the ring of the arylcarbonyl group is unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of a halogen atom, a lower alkyl group, a halo-lower alkyl group, a lower alkoxy group, a cycloalkyl-lower alkoxy group, a hydroxy group, a lower alkoxycarbonyl group, —C(O)NR11R12 and a cyano group,
• f) a heteroarylcarbonyl group, wherein the ring of the heteroarylcarbonyl group is unsubstituted or substituted with 1 to 3 substituents selected from the group consisting of a halogen atom, a lower alkyl group, a halo-lower alkyl group and a lower alkoxy group,
• g) an aralkylcarbonyl group, wherein the ring of the aralkylcarbonyl group is unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of a halogen atom, a lower alkyl group, a halo-lower alkyl group and a lower alkoxy group,
• h) an aryloxy-lower alkylcarbonyl group, wherein the ring of the aryloxy-lower alkylcarbonyl group is unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of a halogen atom, a lower alkyl group, a halo-lower alkyl group and a lower alkoxy group,
• i) a lower alkoxycarbonyl group,
• j) a cycloalkyloxycarbonyl group,
• k) a lower alkoxy-lower alkoxycarbonyl group,
• l) a carboxy group,
• m) a cyano group,
• n) —C(O)NR11R12,
• o) —C(O)C(O)NR11R12,
• p) a lower alkylsulfonyl group,
• q) —SO2NR11R12 or
• r) a heteroaryl group, wherein the ring of the heteroaryl group is unsubstituted or substituted with 1 to 3 substituents selected from the group consisting of a halogen atom, a lower alkyl group, a halo-lower alkyl group and a lower alkoxy group;
• R4 is:
• a) a lower alkyl group,
• b) a halo-lower alkyl group,
• c) a cycloalkyl group,
• d) a heterocycloalkyl group,
• e) a lower alkoxy-lower alkyl group,
• f) an aryloxy-lower alkyl group,
• g) a lower alkoxycarbonyl-lower alkyl group or
• h) a hydroxy-lower alkyl group;
• and
• R11 and R12 are each independently a hydrogen atom, a lower alkyl group, a cycloalkyl group, a bridged cyclic hydrocarbon group, a phenyl group or an aralkyl group, or R11 and R12, together with the nitrogen atom to which they are bonded, form a cyclic amino group.