105591-52-4

Upstream product

• 30779-63-6 6-bromo-2-methyl-4H-chromen-4-one 
• 138-89-6 p-dimethylaminonitrosobenzene 

Downstream Products

• 672327-77-4 4-Nitro-benzoic acid [1-(6-bromo-4-oxo-4H-chromen-2-yl)-meth-(Z)-ylidene]-hydrazide 
• 672327-75-2 2-Chloro-benzoic acid [1-(6-bromo-4-oxo-4H-chromen-2-yl)-meth-(Z)-ylidene]-hydrazide 
• 672327-76-3 4-Methoxy-benzoic acid [1-(6-bromo-4-oxo-4H-chromen-2-yl)-meth-(Z)-ylidene]-hydrazide 
• 672327-74-1 4-Chloro-benzoic acid [1-(6-bromo-4-oxo-4H-chromen-2-yl)-meth-(Z)-ylidene]-hydrazide 
• 672327-73-0 Benzoic acid [1-(6-bromo-4-oxo-4H-chromen-2-yl)-meth-(Z)-ylidene]-hydrazide 

Relevant academic research and scientific papers

Synthesis of 2-dihydrooxadiazolinyl chromones

Reactions of the substituted 2-formyl chromones with aroylhydrazines gave corresponding 2-(aroylhydrazonomethylidyne) chromones. Then 2-(3′-acetyl- 5′-aryl-2′,3′-dihydro-1′,3′,4′-oxadiazol- 2′-yl) chromones were prepared by these 2-(aroylhydrazonomethylidyne) chromones under refluxing with Ac2O. All target compounds were characterized through elemental analysis and IR, 1H NMR, MS.

STUDY OF SUBSTITUTED FORMYLCHROMONES

Substituted derivatives of 2- and 3-formylchromones were synthesized and studied by IR, 13C and 1H NMR spetroscopy and the AM1 quantum chemical method.Energy and electron distribution calculation confirm the preference of synplanar conformation in 3-formylchromones.The calculated charges of the carbon atom correlate well with the experimental 13C chemical shifts.Substituents bonded to the aromatic nucleus have only small effect on the electron structure of the pyrone ring.

Synthesis and Reactions of Some 4-Oxo-4H-1-benzopyran-2-carboxaldehydes

Some new 4-oxo-4H-1-benzopyran-2-carboxaldehydes (III) have been prepared, and the conversion of the 2-carboxaldehyde group in III into 2-carbonitrile and 2-carboxylic acid groups has been discussed.Unlike the general behaviour of the 4-oxo-4H-1-benzopyrans towards some nucleophiles, where the reaction takes place with opening of the pyronering, the 6-methyl- and 6-chloro-4-oxo-4H-1-benzopyran-2-carboxaldehydes (IIIa and IIIb) have been found to react with different nucleophiles such as hydroxylamine hydrochloride, hydrazine, phenylhydrazine and primary aromatic amines to give the corresponding condensation products (IV, VII, VIII, X, XI) without the opening of pyrone ring.The only exception to this observation is the reaction of IIIa and IIIb with ethylene diamine where the opening of pyronering does not take place to give the expected 5,6-dihydropyrazine derivatives (XIIa and XIIb).The reactions of IIIa and IIIb with active methylene compounds, malonic acid, malonodinitrile, cyanoacetic acid, ethyl cyanoacetate, cyanoacetamide and hippuric acid have also been discussed.