Method for producing pyridazinone compounds and intermediate thereof

A compound of the formula (4A):

• wherein the symbols in the formula (4A) are defined as follows:
• R2-4A represents hydrogen, a C1-C6 alkyl group, a (C1-C6 alkoxy)C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C3-C6 cycloalkyl group, a (C1-C6 alkylthio)C1-C6 alkyl group, a (C1-C6 alkylsulfinyl)C1-C6 alkyl group, a (C1-C6 alkylsulfonyl)C1-C6 alkyl group, a phenyl group, or a 5- or 6-membered heteroaryl group;
• wherein the C1-C6 alkyl group, the (C1-C6 alkoxy)C1-C6 alkyl group, the C2-C6 alkenyl group, the C2-C6 alkynyl group, the C3-C6 cycloalkyl group, the (C1-C6 alkylthio)C1-C6 alkyl group, the (C1-C6 alkylsulfinyl)C1-C6 alkyl group, and the (C1-C6 alkylsulfonyl)C1-C6 alkyl group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same or different, the phenyl group and the 5- or 6-membered heteroaryl group may optionally have one or more substituents selected from Group 2-4A, provided that when they have two or more substituents, then the substituents may be same or different;
• the Group 2-4A consists of halogen, a cyano group, a nitro group, a formyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a (C1-C6 alkoxy)C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C3-C6 cycloalkyl group, a C1-C6 alkylthio group, a C1-C6 alkylsulfinyl group, a C1-C6 alkylsulfonyl group, a C1-C6 alkylamino group, a di(C1-C6 alkyl)amino group, a C3-C6 cycloalkylamino group, a (C1-C6 alkyl)carbonyl group, a (C3-C6 cycloalkyl)carbonyl group, a (C1-C6 alkoxy)carbonyl group, a (C1-C6 alkylamino)carbonyl group, a di(C1-C6 alkyl)aminocarbonyl group, a (C3-C6 cycloalkylamino)carbonyl group, and a tri(C1-C6 alkyl)silyl group;
• in the Group 2-4A, the C1-C6 alkyl group, the C1-C6 alkoxy group, the (C1-C6 alkoxy)C1-C6 alkyl group, the C2-C6 alkenyl group, the C2-C6 alkynyl group, the C3-C6 cycloalkyl group, the C1-C6 alkylthio group, the C1-C6 alkylsulfinyl group, the C1-C6 alkylsulfonyl group, the (C1-C6 alkyl)carbonyl group, the (C3-C6 cycloalkyl)carbonyl group, and the (C1-C6 alkoxy)carbonyl group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same or different;
• R3-4A represents hydrogen, a C1-C6 alkyl group, a (C1-C6 alkoxy)C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C3-C6 cycloalkyl group, a (C1-C6 alkylthio)C1-C6 alkyl group, a C1-C6 alkylsulfonyl group, a (C1-C6 alkyl)carbonyl group, a (C1-C6 alkoxy)carbonyl group, a (C1-C6 alkylamino)carbonyl group, a di(C1-C6 alkyl)aminocarbonyl group, a (C3-C6 cycloalkylamino)carbonyl group, a phenyl group, a benzyl group, or a phenylsulfonyl group;
• wherein the C1-C6 alkyl group, the (C1-C6 alkoxy)C1-C6 alkyl group, the C2-C6 alkenyl group, the C2-C6 alkynyl group, the C3-C6 cycloalkyl group, the (C1-C6 alkylthio)C1-C6 alkyl group, the C1-C6 alkylsulfonyl group, the (C1-C6 alkyl)carbonyl group, and the (C1-C6 alkoxy)carbonyl group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same of different;
• and the phenyl group, the benzyl group, and the phenylsulfonyl group may optionally have one or more substituents selected from Group 3-4A, provided that when they have two or more substituents, then the substituents may be same or different;
• the Group 3-4A consists of halogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, and a (C1-C6 alkoxy)C1-C6 alkyl group;
• in the Group 3-4A, the C1-C6 alkyl group, the C1-C6 alkoxy group, and the (C1-C6 alkoxy)C1-C6 alkyl group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same or different;
• R5-4A represents a C1-C6 alkyl group or a phenyl group;
• wherein the C1-C6 alkyl group may be optionally substituted with one or more halogens, provided that when it is substituted with two or more halogens, then the halogens may be same or different;
• and the phenyl group may optionally have one or more substituents selected from Group 5-4A, provided that when it has two or more substituents, then the substituents may be same or different;
• the Group 5-4A consists of halogen, a C1-C6 alkyl group, and a C1-C6 alkoxy group;
• in the Group 5-4A, the C1-C6 alkyl group, and the C1-C6 alkoxy group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same or different;
• G4A represents a C6-C10 aryl group, a 5- or 6-membered heteroaryl group, or an 8- to 10-membered fused heteroaryl group;
• wherein the C6-C10 aryl group, the 5- or 6-membered heteroaryl group, and the 8- to 10-membered fused heteroaryl group may optionally have one or more substituents selected from Group R4-4A, provided that when they have two or more substituents, then the substituents may be same or different;
• the Group R4-4A consists of halogen, a cyano group, a nitro group, a formyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a (C1-C6 alkoxy)C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C3-C6 cycloalkyl group, a C1-C6 alkylthio group, a C1-C6 alkylsulfinyl group, a C1-C6 alkylsulfonyl group, a C1-C6 alkylamino gout), a di(C1-C6 alkyl)amino group, a C3-C6 cycloalkylamino group, a (C1-C6 alkyl)carbonyl group, a (C3-C6 cycloalkyl)carbonyl group, a (C1-C6 alkoxy)carbonyl group, a (C1-C6 alkylamino)carbonyl group, a di(C1-C6 alkyl)aminocarbonyl group, a (C3-C6 cycloalkylamino)carbonyl group, a tri(C1-C6 alkyl)silyl group, a C6-C10 aryl group, and a 5- or 6-membered heteroaryl group;
• in the Group R44A, the C1-C6 alkyl group, the C1-C6 alkoxy group, the (C1-C6 alkoxy)C1-C6 alkyl group, the C2-C6 alkenyl group, the C2-C6 alkynyl group, the C3-C6 cycloalkyl group, the C1-C6 alkylthio group, the C1-C6 alkylsulfinyl group, the C1-C6 alkylsulfonyl group, the (C1-C6 alkyl)carbonyl group, the (C3-C6 cycloalkyl)carbonyl group, and the (C1-C6 alkoxy)carbonyl group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same or different;
• and the C6-C10 aryl group and the 5- or 6-membered heteroaryl group may optionally have one or more substituents selected from Group 4-4A, provided that when they have two or more substituents, then the substituents may be same or different;
• the Group 4-4A consists of halogen, a cyano group, a nitro group, a formyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a (C1-C6 alkoxy)C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C3-C6 cycloalkyl group, a C1-C6 alkylthio group, a C1-C6 alkylsulfinyl group, a C1-C6 alkylsulfonyl group, a C1-C6 alkylamino mow, a di(C1-C6 alkyl)amino group, a C3-C6 cycloalkylamino group, a (C1-C6 alkyl)carbonyl group, a (C3-C6 cycloalkyl)carbonyl group, a (C1-C6 alkoxy)carbonyl group, a (C1-C6 alkylamino)carbonyl group, a di(C1-C6 alkyl)aminocarbonyl group, a (C3-C6 cycloalkylamino)carbonyl group, and a tri(C1-C6 alkyl)silyl group;
• in the Group 4-4A, the C1-C6 alkyl group, the C1-C6 alkoxy group, the (C1-C6 alkoxy)C1-C6 alkyl group, the C2-C6 alkenyl group, the C2-C6 alkynyl group, the C3-C6 cycloalkyl group, the C1-C6 alkylthio group, the C1-C6 alkylsulfinyl group, the C1-C6 alkylsulfonyl group, the (C1-C6 alkyl)carbonyl group, the (C3-C6 cycloalkyl)carbonyl group, and the (C1-C6 alkoxy)carbonyl group may be optionally substituted with one or more halogens, provided that when they are substituted with two or more halogens, then the halogens may be same or different;
• and
• n represents an integer of 0, 1 or 2.