- Synthesis of Pyridazine Derivatives via Aza-Diels-Alder Reactions of 1,2,3-Triazine Derivatives and 1-Propynylamines
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A highly regioselective method was developed for the preparation of pyridazine derivatives via the aza-Diels-Alder reaction of 1,2,3-triazines with 1-propynylamines under neutral conditions. This methodology allowed direct access to a wide range of 6-aryl-pyridazin-3-amines in high yields with good functional group compatibility. Key features of this strategy included a broad substrate scope and simple, metal-free, and neutral reaction conditions.
- Kodama, Takayuki,Sasaki, Ikuo,Sugimura, Hideyuki
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p. 8926 - 8932
(2021/07/19)
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- Synthesis and Structure-Activity Relationships of Series of Aminopyridazine Derivatives of γ-Aminobutyric Acid Acting as Selective GABA-A Antagonists
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We have recently shown that an aryloaminopyridazine derivarive of GABA, SR 95103 , is a selective and competitive GABA-A receptor antagonist.In order to further explore the structural requirements for GABA receptor affinity, we synthesized a series of 38 compounds by attaching various pyridazinic structures to GABA or GABA-like side chains.Most of the compounds displaced GABA from rat brain membranes.All the active compounds antagonized the GABA-elicited enhancement of diazepam binding, strongly suggesting that all these compounds are GABA-A receptor antagonists.None of the compounds that displaced GABA from rat brain membranes interacted with other GABA recognition sites (GABA-B receptor, GABA uptake binding site, glutamate decarboxylase, GABA-transaminase).They did not interact with the Cl- ionophore associated with the GABA-A receptor and did not interact with the benzodiazepine, strychnine, and glutamate binding sites.Thus these compounds appear to be specific GABA-A receptor antagonists.In terms of structure-activity, it can be concluded that a GABA moiety bearing a positive charge is necessary for optimal GABA-A receptor recognition.Additional binding sites are tolerated only if they are part of a charge-delocalized amidinic or guanidinic system.If this delocalization is achieved by linking a butyric acid moiety to the N(2) nitrogen of a 3-aminopyridazine, GABA-antagonistic character is produced.The highest potency (ca.250 times bicuculline) was observed when an aromatic ? system, bearing electron-donating substituents, was present on the 6-position of the pyridazine ring.
- Wermuth, Camille-Georges,Bourguignon, Jean-Jacques,Schlewer, Gilbert,Gies, Jean-Pierre,Schoenfelder, Angele,et al.
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p. 239 - 249
(2007/10/02)
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- Herbicidal pyridazines and method for controlling undesirable plant species
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This invention relates to a method for controlling undesirable monocotyledonous and dicotyledonous plant species by applying to the foliage thereof or to soil containing seeds or other propagating organs of said plant species, a herbicidally-effective amo
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- Reactions of 3-Chloropyridazines with Some Nucleophilic Reagents
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3-Chloro-6-phenylpyridazine (1a) and its 4-methyl derivative (1b) react with sodamide, hydrazines, 3-aminopyridazines and phenothiazine in polar and non-polar solvents as well as by fusion to give different products.The structures assigned to the products have been confirmed by their IR spectra.
- Moustafa, A. H.,Kaddah, A. M.,Shams, N. A.
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p. 1084 - 1086
(2007/10/02)
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