Pyridone derivatives and herbicides

A compound of the formula:

• wherein
• R is a C1-C6 haloalkyl group;
• R2′ is a hydrogen atom or a C1-C6 alkyl group;
• R19′ is a hydrogen atom or a C1-C6 alkyl group, and Q′ represents a formula of
• wherein
• R3 represents a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C1-C4 haloalkyl group, a C1-C6 alkoxy group, a C1-C6 alkyl carbonyl group, a C1-C6 alkoxy carbonyl group, a halogen atom, a nitro group, or a cyano group,
• R20 represents a hydrogen atom, a halogen atom, a hydroxyl group, a C1-C6 alkoxy group, a C3-C6 alkenyloxy group, a C3-C6 alkynyloxy group, a C1-C6 haloalkoxy group, a C3-C6 haloalkenyloxy group, or a group of —NR11R12,
• R11 represents a hydrogen atom, a C1-C6 alkyl group, a C3-C6 alkenyl group, a C3-C6 alkynyl group a C3-C8 cycloalkyl group, a C1-C6 haloalkyl group, a C3-C6 haloalkenyl group, a C1-C6 alkoxycarbonyl group, or a C3-C8 cycloalkyl C1-C6 alkyl group,
• R12 represents a hydrogen atom a C1-C6 alkyl group, a C3-C6 alkenyl group, a C3-C6 alkynyl group, a C3-C8 cycloalkyl group, C1-C6 haloalkyl group, a C3-C6 haloalkenyl group, a C1-C6 alkylcarbonyl group, a C1-C6 alkoxycarbonyl group, or a C3-C8 cycloalkyl C1-C6 alkyl group,
• R4′ is a hydrogen atom, a halogen atom or a nitro group;
• R5′ is a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C1-C6 haloalkyl group, a nitro group, a group of —YR9′, a group of —SOR9′, a group of —SO2R9′ or a C1-C6 alkoxy C1-C6 alkyl group.