Novel heterocyclic compound

A compound of the formula (1′):

• wherein R1′ and R2′ are independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted saturated heterocyclic group, or R1′ and R2′ combine together with the adjacent nitrogen atom to which they bond, and form a group of the formula (4):
• (in which n is 0 or 1, m is 1, 2 or 3, Y is a single bond, an oxygen atom or a sulfur atom, Q is methylene, ethylene, or an optionally substituted o-phenylene group);
• R3 and R4 are independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, or an optionally substituted alkynyl group;
• R5, R6, R7 and R8 are independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, a halogen atom, a cyano group, a nitro group, a hydroxy group, an optionally substituted amino group, an optionally substituted alkoxy group, an optionally substituted alkanoyl group, an optionally substituted alkoxycarbonyl group, an optionally substituted aryloxycarbonyl group, an optionally substituted heteroaryloxycarbonyl group, a carboxyl group, an optionally substituted carbamoyl group, an optionally substituted sulfamoyl group, an optionally substituted ureido group, an optionally substituted alkylthio group, an optionally substituted alkylsulfinyl group, an optionally substituted alkylsulfonyl group, or a group of the formula:
• -E-A (in which E is a single bond, an oxygen atom, a sulfur atom, —SO—, —SO2—, —NR9— or —CO—, A is an optionally substituted aryl group or an optionally substituted heteroaryl group, and R9 is a hydrogen atom or an optionally substituted alkyl group);
• X is an oxygen atom, a sulfur atom, NR10, or CR11R12 (in which R10 is a hydrogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted alkanoyl group, or an optionally substituted alkoxycarbonyl group, R11 and R12 are independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, a halogen atom, a cyano group, a hydroxy group, an optionally substituted amino group, an optionally substituted alkoxy group, an optionally substituted aryloxy group, an optionally substituted alkanoyl group, an optionally substituted aroyl group, an optionally substituted heteroarylcarbonyl group, an optionally substituted alkoxycarbonyl group, a carboxyl group, or an optionally substituted carbamoyl group, or R11 and R12 combine and form an oxo group or ═NOH);
• Alternatively,
• (i) when X is NR10, then by combining R8 and R10, the formula (1′) may be expressed by the formula (2′):
• wherein R1′, R2′, R3, R4, R5, R6 and R7 are as defined above, Z1 is an optionally substituted alkylene group, and one of the carbon atoms of said alkylene group can be replaced by an oxygen atom, a sulfur atom or —NR13— (in which R13 is a hydrogen atom or an optionally substituted alkyl group), and a double bond may be formed between any adjacent atoms of said alkylene group;
• (ii) by combining R4 and R5, the formula (1′) may be expressed by the formula (3′):
• wherein R1′, R2′, R3, R6, R7, R8 and X are as defined above, Z2 is an optionally substituted alkylene group, and one of the carbon atoms of said alkylene group can be replaced by an oxygen atom, a sulfur atom or —NR13— (in which R13 is a hydrogen atom or an optionally substituted alkyl group), and a double bond may be formed between any adjacent atoms of said alkylene group,
• provided that in cases other than the above (i) or (ii),
• (1) R1′ and R2′ are not simultaneously a hydrogen atom,
• (2) R1′ or R2′ is not a saturated heterocyclic group,
• (3) when R1′ and R2′ combine together with the adjacent nitrogen atom to which they bond and form a group of the formula (4), then Q is an optionally substituted o-phenylene group,
• (4) R5, R6, R7 and R8 are not simultaneously a hydrogen atom,
• (5) when one or two groups of R5, R6, R7 and R8 are independently a halogen atom or an optionally substituted alkyl group, then the remaining groups are not a hydrogen atom,
• (6) when X is a sulfur atom, and one or two groups of R5, R6, R7 and R8 are independently a halogen atom, a nitro group, an alkyl group, a halogen-substituted alkyl group, an alkoxy group, or an optionally substituted amino group, then the remaining groups are not a hydrogen atom,
• (7) when X is an oxygen atom, and one or two groups of R5, R6, R7 and R8 are independently a halogen atom, an alkoxy group, or an optionally substituted arylcarbonyl group, and the remaining groups are a hydrogen atom, then R1′ or R2′ is not a hydrogen atom,
• (8) when X is an oxygen atom, R7is a nitro group, and R5, R6 and R8 are a hydrogen atom, then R1′ and R2′ are not simultaneously an alkyl group,
• (9) when X is NR10, and one or two groups of R5, R6, R7 and R8 are independently an optionally substituted alkyl group, an optionally substituted alkoxy group, a halogen atom, or a cyano group, then the remaining groups are not a hydrogen atom,
• (10) when X is CR11R12, then R11 and R12 are independently a hydrogen atom, an alkyl group optionally substituted by a halogen atom, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, or an optionally substituted alkynyl group, or R11 and R12 combine each other and form an oxo group or ═NOH, and R1′ or R2′ is not a hydrogen atom, or a prodrug thereof, or a pharmaceutically acceptable salt thereof.