Annulated pyridazine compound

A compound of formula (I):

• or a salt thereof, wherein
• ring A is C5-8 cycloalkenyl, 5- to 11-membered partially unsaturated heterocyclyl, aryl, or heteroaryl;
• R1, which are identical or different from each other, are OH, C1-6 alkyl, halogeno C1-6 alkyl, C3-8 cycloalkyl, halogen, cyano, —O—C1-6 alkyl, —O-halogeno C1-6 alkyl, or —O—C3-8 cycloalkyl;
• R2, which are identical or different from each other, are C1-6 alkyl, —C1-6 alkylene-aryl, C3-8 cycloalkyl, halogen, —O—C1-6 alkyl, —O-halogeno C1-6 alkyl, oxo, —C(O)—C1-6 alkyl, or —S(O)2—C1-6 alkyl;
• L is —NR3—, —O—, or —CR4R5—;
• R3 is H or C1-6 alkyl;
• R4 and R5, which are identical or different from each other, are H or C1-6 alkyl;
• R6 is C1-6 alkyl substituted with one to four identical or different R7, —C1-6 alkylene-(C3-8 cycloalkyl optionally substituted with one to four identical or different R8), —C1-6 alkylene-(4- to 7-membered saturated heterocyclyl optionally substituted with one to four identical or different R9), C3-8 cycloalkyl optionally substituted with one to four identical or different R10 or 4- to 7-membered saturated heterocyclyl optionally substituted with one to four identical or different R11;
• R7 is —OR12, —NR13R14, halogen, or cyano;
• R8 and R10 are C1-6 alkyl, halogeno C1-6 alkyl, C3-8 cycloalkyl, —OR12, —NR13R14, —C1-6 alkylene-OR12, —C1-6 alkylene-NR13R14, halogen, or cyano;
• R9 and R11 are C1-6 alkyl, halogeno C1-6 alkyl, C3-8 cycloalkyl, 4- to 7-membered saturated heterocyclyl, —OR12, —NR13R14, —C1-6 alkylene-OR12, —C1-6 alkylene-NR13R14, halogen, cyano, oxo, —C(O)—C1-6 alkyl, or —S(O)2—C1-6 alkyl;
• R12 is H or C1-6 alkyl;
• R13 and R14, which are identical or different from each other, are H, C1-6 alkyl, or —C(O)—C1-6 alkyl;
• n is an integer of 1 to 4 and represents the number of substituents R1;
• and
• m is an integer of 0 to 3 and represents the number of substituents R2,
• provided that when ring A is aryl or heteroaryl, formula (I) is formula (Ia):
• R1a, which are identical or different from each other, are C1-6 alkyl, halogeno C1-6 alkyl, C3-8 cycloalkyl, halogen, cyano, —O—C1-6 alkyl, —O-halogeno C1-6 alkyl, or —O—C3-8cycloalkyl;
• and
• k is an integer of 0 to 3 and represents the number of substituents R1a.