1457-42-7

Basic information

• Product Name: Pyridazine N-oxide
• Synonyms: PYRIDAZINE-N-OXIDE;Pyridazine 1-oxide;4-chlorine-5-Mi oxide pyridazine -3(2H)-ketone;Pyridazine N-oxide 97%;1-oxidopyridazin-1-ium
• CAS NO: 1457-42-7
• Molecular Formula: C₄H₄N₂O
• Molecular Weight: 96.09
• EINECS: 200-001-2
• Mol File: 1457-42-7.mol
• Article Data: 12

Chemical Properties

• Melting Point: 298-305 °C
• Boiling Point: 210.7°Cat760mmHg
• Flash Point: 81.2°C
• Appearance: /
• Density: 1.19g/cm³
• Vapor Pressure: 0.275mmHg at 25°C
• Refractive Index: 1.564
• CAS DataBase Reference: Pyridazine N-oxide(CAS DataBase Reference)
• NIST Chemistry Reference: Pyridazine N-oxide(1457-42-7)
• EPA Substance Registry System: Pyridazine N-oxide(1457-42-7)

Safety Data

• Hazard Codes: Xn
• Statements: 22-37/38-41
• Safety Statements: 26-39
• RIDADR: UN 3335
• WGK Germany: 3
• Hazardous Substances Data: 1457-42-7(Hazardous Substances Data)

Usage

Uses

Coupling partner in Pd-catalyzed direct arylation reactions.

Purification Methods

Purify the oxide by distillation in a vacuum and by sublimation in vacuo. When a solution of the oxide in MeOH is treated with an aqueous solution of CuCl2, the [C4H4N2O]2—CuCl2-2H2O-complex (m 182-183o) is formed from which the oxide can be recovered . [Pollak et al. J Org Chem 35 2478 1970, Klinge et al. Recl Trav Chim, Pays Bas 95 21 1976, Ohsawa et al. Tetrahedron Lett 1979 1978, Koelsch & Gumprecht J Org Chem 23 1605 1958, Beilstein 23 III/IV 890.]

InChI:InChI=1/C4H4N2O/c7-6-4-2-1-3-5-6/h1-4H

Upstream product

• 289-80-5 1,2-diazine 
• 71246-74-7 4-(3-cyano-1-triazeno)pyridazine 1-oxide potassium salt 

Downstream Products

• 19883-27-3 (3E,5Z)-1,3,5-undecatriene 
• 16356-11-9 (3E,5E)-1,3,5-undecatriene 
• 85615-64-1 undecatriene-2Z,4Z,6E 
• 132643-65-3 9-Oxa-2-aza-benzocycloheptene 
• 132643-66-4 5-Oxa-2-aza-benzocycloheptene 
• 108563-78-6 9-Oxa-1-aza-benzocycloheptene 
• 51447-08-6 (1,3Z,5E)-undeca-1,3,5-triene 
• 289-80-5 1,2-diazine 
• 109-97-7 pyrrole 
• 928-53-0 maleonitrile 
• 107-13-1 acrylonitrile 
• 764-42-1 1,2-Dicyanoethylene 
• 1262526-08-8 6-(3,4,5-trimethylphenyl)pyridazine 1-oxide 
• 1262526-10-2 6-(4-methoxycarbonylphenyl)pyridazine 1-oxide 

Relevant articles and documents

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Experimental and theoretical molecular and electronic structures of the N-oxides of pyridazine, pyrimidine and pyrazine

The structures of pyridazine N-oxide, pyrimidine N-oxide and pyrazine N-oxide have been determined by X-ray diffraction for the first time. Comparison with theoretical predictions of the equilibrium structures using the B3LYP method together with a cc-pVTZ basis set, show close agreement with the structural parameters observed, and experimental dipole moments, which suggests that the charge distribution is realistic. An 'atoms in molecules' (AIM) analysis of the computed wave-functions shows total electron densities rather different from the classical picture of a dative bond, whereas the same wave-functions subjected to Mulliken analysis show a more conventional view of the electron distribution. This latter procedure allows a bond dipole analysis of the N-oxide charge distribution.

Pd-Catalyzed Direct C-H Alkenylation and Allylation of Azine N -Oxides

A Pd-catalyzed direct C2-alkenylation of azine N-oxides with allyl acetate is disclosed. The products are formed through an allylation/isomerization cascade process. The use of a tri-tert-butylphosphonium salt as the ligand precursor and KF is mandatory for optimal yields. When cinnamyl acetate is used, the same catalytic system promotes C2-cinnamylation of the azine N-oxide without subsequent isomerization. A mechanism is proposed on the basis of experimental studies and DFT calculations.

Synthesis of N,N-Dioxopyridazines

Despite many efforts, one of the smallest heterocycles containing two nitrogen atoms, pyridazine, could not be converted to its N,N-dioxide (see, however, Nakadate et al. Chem. Pharm. Bull. 1970, 18, 1211-1218). HOF·CH3CN, made easily from diluted fluorine, was able to accomplish this task in a fast reaction with good yields.