Amidine compounds and herbicides

Amidine compounds represented by a formula (1′)

• or a salt thereof:
• wherein G′ represents an optionally substituted pyrrolidine-1-yl group;
• Q′ represents cyano;
• A′ is a group represented by a formula (4′)
• wherein X represents halogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, optionally substituted C1-6 alkyl carbonyl, optionally substituted C2-6 alkenyl carbonyl, optionally substituted C2-6 alkynyl carbonyl, optionally substituted aryl carbonyl, optionally substituted C1-6 alkylthiocarbonyl, optionally substituted C2-6 alkenylthiocarbonyl, optionally substituted C2-6 alkynylthiocarbonyl, optionally substituted arylthiocarbonyl, cyano, substitutent represented by X11, optionally substituted amino, nitro, hydroxyl, optionally substituted C1-6 alkoxy, optionally substituted C2-6 alkenyloxy, optionally substituted C2-6 alkynyloxy, optionally substituted aryloxy, optionally substituted heteroyloxy, mercapto, optionally substituted C1-6 alkylthio, optionally substituted C2-6 alkenylthio, optionally substituted C2-6 alkynylthio, optionally substituted arylthio, optionally substituted heteroylthio, optionally substituted alkyl sulfinyl, optionally substituted aryl sulfinyl, optionally alkyl sulfonyl, optionally substituted aryl sulfonyl, or an optionally substituted heterocyclic group;
• and
• substitutents which are in positions that are bondable with each other may bond together to form rings;
• n′ is an integer of 2 to 5 and each X may be the same or different from each other;
• X11 is a substituent represented by a formula (5)
• wherein m1 represents an integer of 0 to 3;
• A1 represents an atom selected from carbon, nitrogen, oxygen, and sulfur, and which may be oxidized within a chemically acceptable range and which may be substituted;
• when m1 is 2 or more, each A1 may be the same or different from each other and combinations of each A1 are within a chemically acceptable range and each A1 may, within a chemically acceptable range of multiplicity, bond to each other;
• and
• when A1 is carbon and one or more A1 is substituted by two or more substitutents, the substituents which are in a bondable positional relationship may bond together to form a ring;
• Z1 represents a group represented by —OR11 or —NR12R13;
• R11 represents hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, an optionally substituted heterocyclic group, or a group represented by X12;
• R12 and R13 each independently represents hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, an optionally substituted heterocycle, a group represented by X12, hydroxyl, optionally substituted C1-6 alkoxy, optionally substituted C2-6 alkenyloxy, optionally substituted C2-6 alkynyloxy, optionally substituted aryloxy, optionally substituted alkyl sulfinyl, optionally substituted aryl sulfinyl, optionally substituted alkyl sulfonyl, optionally substituted aryl sulfonyl, or optionally substituted amino;
• and
• R12 and R13 may further bond together to form a ring;
• X12 is a substituent represented by a group (6)
• wherein m2 is an integer of 1 to 3,
• A2 represents optionally substituted carbon and may be substituted within a chemically acceptable range and when m2 is 2 or more, each A2 may bond to each other within a chemically acceptable range of multiplicity;
• and
• when one or more A2 is substituted by two or more substituents, the substituents which are in a bondable positional relationship may bond together to form a ring;
• Y represents oxygen or optionally substituted nitrogen;
• Z2 is a group represented by —OR21 or —NR22R23 when Y is oxygen and Z2 represents hydrogen or optionally substituted C1-6 alkyl when Y is nitrogen;
• R21 represents hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, an optionally substituted heterocycle, or a group represented by X13;
• R22 and R23 each independently represent hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, optionally substituted heterocycle, a group represented by X13, optionally substituted C1-6 alkoxy, optionally substituted C2-6 alkenyloxy, optionally substituted C2-6 alkynyloxy, optionally substituted aryloxy, optionally substituted alkyl sulfinyl, optionally substituted aryl sulfinyl, optionally substituted alkyl sulfonyl, or optionally substituted aryl sulfonyl;
• and R22 and R23 may bond together to form a ring when neither is hydrogen;
• X13 is a substituent represented by a formula (7)
• wherein m3 is an integer of 1 to 3;
• A3 represents optionally substituted carbon and may be substituted within a chemically acceptable range, and when m3 is 2 or more, each A3 may bond to each other within a chemically acceptable range of multiplicity;
• and
• when one or more A3 is substituted by two or more substituents, the substituents which are in a bondable positional relationship may bond together to form a ring;
• Z3 is a group represented by —OR31 or —NR32R33;
• R31 represents hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, or an optionally substituted heterocyclic group;
• R32 and R33 each independently represents hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C2-6 alkynyl, optionally substituted aryl, optionally substituted heterocycle, optionally substituted C1-6 alkoxy, optionally substituted C2-6 alkenyloxy, optionally substituted C2-6 alkynyloxy, optionally substituted aryloxy, optionally substituted alkyl sulfinyl, optionally substituted aryl sulfinyl, optionally substituted alkyl sulfonyl, or optionally substituted aryl sulfonyl;
• and R32 and R33 may further bond together to form a ring when neither is hydrogen).