32723-45-8

Upstream product

• 28657-39-8 3-chloro-4-methyl-6-phenylpyridazine 
• 130223-67-5 1-benzoyl-6-methoxy-4a,6-dimethyl-3-phenyl-1,4,4a,7a-hexahydrofuro<2,3-e>pyridazine 
• 928-55-2 ethyl 1-propenyl ether 
• 71094-28-5 N′-(2-chloro-1-phenylethylidene)-4-methylbenzenesulfonohydrazide 
• 4696-26-8 (E)-1-ethoxyprop-1-ene 
• 170650-70-1 ethyl (2,2-dichloro-1-phenylethylidene)hydrazinecarboxylate 
• 532-27-4 1-chloroacetophenone 
• 52813-35-1 3-methyl-1-phenylbut-3-en-1-one 
• 130223-65-3 α-chloroacetophenone benzoylhydrazone 
• 25445-76-5 N-ethoxycarbonyl-N'-(1-phenyl-ethylidene)-hydrazine 
• 1074-12-0 phenylglyoxal hydrate 
• 130223-66-4 1-benzoyl-4a,6-dimethyl-3-phenyl,1,4,4a,7a-tetrahydrofuro<2,3-e>pyridazine 
• 98-86-2 acetophenone 

Downstream Products

• 32723-51-6 5-methyl-3-phenylpyridazine 1-oxide 

Relevant academic research and scientific papers

Synthesis of 1,4,5,6-tetrahydropyridazines and pyridazines: Via transition-metal-free (4 + 2) cycloaddition of alkoxyallenes with 1,2-diaza-1,3-dienes

We developed an economical and practical protocol for the synthesis of 1,4,5,6-tetrahydropyridazines. A diverse range of alkoxyallenes and 1,2-diaza-1,3-dienes undergo (4 + 2) cycloaddition to generate the desired products in excellent yields. The high efficiency, wide substrate scope and good functional group tolerance of this process, coupled with operational simplicity, render the method synthetically attractive. The utility of the cycloaddition is also demonstrated by the preparation of various pyridazines from 1,4,5,6-tetrahydropyridazines.

Copper-catalyzed aerobic 6-endo-trig cyclization of β,γ-Unsaturated Hydrazones for the Divergent Synthesis of Dihydropyridazines and Pyridazines

A divergent synthetic strategy to 1,6-dihydropyridazines and pyridazines through Cu(II)-catalyzed controllable aerobic 6-endo-trig cyclization was developed. The selectivity can be rationally tuned via the judicious choice of reaction solvent. It was found that the 1,6-dihydropyridazines were obtained in moderate to high yields with CH3CN as the reaction solvent, whereas employment of AcOH directly afforded pyridazines in up to 92% yields, probably arising from the oxidation of the in situ generated 1,6-dihydropyridazines.

Pyridazine N-Oxides as Precursors of Metallocarbenes: Rhodium-Catalyzed Transannulation with Pyrroles

Pyridazine N-oxides are used for the first time as precursors of metallocarbenes. These nitrogen-rich heterocycles led to the discovery of a novel acceptor and donor-acceptor enalcarbenoids. The synthetic utility of these metallocarbenes was demonstrated in the rhodium-catalyzed denitrogenative transannulation of pyridazine N-oxides with pyrroles to the valuable alkyl, 7-aryl, and 7-styryl indoles. The transannulation strategy was applied to the synthesis of a potent anticancer agent.

Metallo-Aldehyde Enolates via Enal Hydrogenation: Catalytic Cross Aldolization with Glyoxal Partners As Applied to the Synthesis of 3,5-Disubstituted Pyridazines

Aldehyde enolates generated through rhodium-catalyzed enal hydrogenation are subject to electrophilic trapping by exogenous glyoxal partners to afford β-hydroxy-γ-keto-aldehyde products, which upon exposure to hydrazine afford 3,5-disubstituted pyridazine

Synthesis and reactions of haloazodienes. A new and general synthesis of substituted pyridazines

The reaction of dihalohydrazones with Hunig's base gives 1-carbethoxy-3-phenyl-4-haloazodienes in-situ, which were found to combine with a variety of electron rich olefins to yield halo-substituted tetrahydropynidazines. These haloazodiene cyclizations are best characterized as inverse electron demand, 4 + 2 hetero Diels-Alder reactions that maintain a high degree of regio- and stereochemical control. The chloro-substituted tetrahydropyridazines that are formed give high yields of substituted pyridazines upon treatment with base. The sequence of a chloroazodiene cyclization to a tetrahydropyridazine followed by an aromatization constitutes a new and general synthesis of substituted pyridazines. In contrast to the haloazodiene cyclizations, the novel cyclization reactions of the in-situ generated 1-carbethoxy-3-phenyl-4,4-dichloroazodiene were found to give N-aminopyrroles and pyridazines when combined with acyclic enamines. However, reactions with cyclic enamines gave the N-aminopyrroles, pyridazines, a dihydropyridazine as products as well as the noncyclized enamine intermediates. The noncyclized enamines could be converted to the N-aminopyrroles simply upon heating to higher temperatures, indicating a stepwise mechanism. The examples described here are the first reported cyclization reactions for dichloroazodienes.

Synthesis and reactions of chloroazodienes. A new and general synthesis of pyridazines

The reaction of dichlorohydrazones with Hunig's base gives 4-chloroazodienes, which were found to combine with a variety of electron rich olefins to yield chloro-substituted tetrahydropyridazines. These chloroazodiene cyclizations are best characterized a

Competitive and Cycloadditions of Nitrosoalkenes to the Imino Bond of Bicyclic 1,2-Oxazines

The bicyclic 1,2-oxazines derived from the cycloaddition of α-nitrosostyrene to either 2,5-dimethylfuran (11) or cyclopentadiene (15) react further with nitrosostyrene or other nitrosoalkenes.Only 3 + 2 addition is observed with (11) to give the tricyclic

1,4,5,6-Tetrahydropyridazines by Cycloaddition of Enol Ethers to Azoalkenes and their Aromatisation to Pyridazines.

Transient azoalkenes generated from acyl- and 4-tolylsulphonyl-hydrazones of α-haloacetophenones and of ethyl bromopyruvate are intercepted by cycloaddition to enol ethers, giving 6-alkoxy-1,4,5,6-tetrahydropyridazines (2). 6-Alkoxy-3-aryl-1,4,5,6-tetrahydropyridazines are converted by reaction with sodium ethoxide into 3-arylpyridazines (3).