The present invention provides an industrially-advantageous process for preparing a benzoyl formic acid compound, and an efficient process for preparing a pyridazine compound using the same process. Specifically, the present invention provides a process for preparing a compound represented by formula (2), which comprises a step (B): a step of reacting a compound represented by formula (1) with a nitrosyl sulfuric acid in water to produce the compound represented by formula (2).

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The present invention provides an industrially-advantageous process for preparing a benzoyl formic acid compound, and an efficient process for preparing a pyridazine compound using the same process. Specifically, the present invention provides a process for preparing a compound represented by formula (2), which comprises a step (B): a step of reacting a compound represented by formula (1) with a nitrosyl sulfuric acid in water to produce the compound represented by formula (2).

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Provided herein is a process for preparing a pyridazine amine compound of formula V, and a process for preparing dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof. Further, provided herein are novel dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof, wherein the amino group is an ethylamino group.

Provided herein is a process for preparing a pyridazine amine compound of formula V, and a process for preparing dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof. Further, provided herein are novel dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof, wherein the amino group is an ethylamino group.

Provided herein is a process for preparing a pyridazine amine compound of formula V, and a process for preparing dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof. Further, provided herein are novel dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof, wherein the amino group is an ethylamino group.

Provided herein is a process for preparing a pyridazine amine compound of formula V, and a process for preparing dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof. Further, provided herein are novel dichloropyridazine amine compounds of formula IVa, IVb, and mixtures thereof, wherein the amino group is an ethylamino group.

The invention relates to the use of a compound of formula (I)

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or a salt thereof for combating animal pests,
where the symbols and indices are defined in the specification.

The invention relates to the use of a compound of formula (I)

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or a salt thereof for combating animal pests,
where the symbols and indices are defined in the specification.

The present invention relates to (6-((octahydrocyclopenta[c]pyrrol-5-yl)amino)pyridazin-3-yl)benzamide (R2b is C(O)N(RA1)(RA2) and N-(6-((octahydrocyclopenta[c]pyrrol-5-yl)amino)pyridazin-3-yl) phenyl) carboxamide (R2b is N(RB)C(O)RC) derivatives of formula (I) wherein (II) R.sup.2b is C(O)N(R.sup.A1)(R.sup.A2) or N(R.sup.B)C(O)R.sup.C as antagonists of the muscarinic acetylcholine receptor M4 (mAChR M4) for the treatment of neurodegenerative disorders, movement disorders or brain disorders, such as e.g. Parkinson's disease, drug-induced Parkinsonism, dystonia, Tourette's syndrome, dyskinesias, schizophrenia, cognitive deficits associated with schizophrenia, excessive daytime sleepiness, attention deficit hyperactivity disorder (ADHD), Huntington's disease, chorea, cerebral palsy, and progressive supranuclear palsy. An exemplary compound is e.g. N-(4-(6-(((3aR,5s,6aS)-2-(2-fluorobenzyl)octahydrocyclopenta[c]pyrrol-5-yl)amino)pyridazin-3-yl) phenyl)acetamide (A1) (III).

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The present invention relates to (6-((octahydrocyclopenta[c]pyrrol-5-yl)amino)pyridazin-3-yl)benzamide (R2b is C(O)N(RA1)(RA2) and N-(6-((octahydrocyclopenta[c]pyrrol-5-yl)amino)pyridazin-3-yl) phenyl) carboxamide (R2b is N(RB)C(O)RC) derivatives of formula (I) wherein (II) R.sup.2b is C(O)N(R.sup.A1)(R.sup.A2) or N(R.sup.B)C(O)R.sup.C as antagonists of the muscarinic acetylcholine receptor M4 (mAChR M4) for the treatment of neurodegenerative disorders, movement disorders or brain disorders, such as e.g. Parkinson's disease, drug-induced Parkinsonism, dystonia, Tourette's syndrome, dyskinesias, schizophrenia, cognitive deficits associated with schizophrenia, excessive daytime sleepiness, attention deficit hyperactivity disorder (ADHD), Huntington's disease, chorea, cerebral palsy, and progressive supranuclear palsy. An exemplary compound is e.g. N-(4-(6-(((3aR,5s,6aS)-2-(2-fluorobenzyl)octahydrocyclopenta[c]pyrrol-5-yl)amino)pyridazin-3-yl) phenyl)acetamide (A1) (III).

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