33288-76-5

Upstream product

• 1226-42-2 1,2-bis(4-methoxyphenyl)-1,2-ethanedione 
• 107-15-3 ethylenediamine 
• 119-52-8 4,4'-dimethoxybenzoin 
• 6780-13-8 1,2-ethanediamine monohydrate 

Downstream Products

• 92405-83-9 2,3-bis(4-methoxy phenyl)pyrazine 
• 77375-46-3 4,4'-dimethoxy-benzil-dihydrazone 
• 107-15-3 ethylenediamine 
• 122956-28-9 5,6-bis(4-methoxyphenyl)-pyrazine-2-carboxylic acid 
• 92405-97-5 5,6-bis(p-methoxyphenyl)-2,3-diacetoxy-2,3-dihydropyrazine 
• 92405-90-8 2,3-bis(p-methoxyphenyl)pyrazine 1-oxide 
• 92405-91-9 2,3-bis(p-methoxyphenyl)pyrazine 1,4-dioxide 

Relevant academic research and scientific papers

Solvent effect on the sensitized photooxygenation of cyclic and acyclic α-diimines

The reaction of singlet molecular oxygen with a series of cyclic and acyclic α-diimines was studied. Time-resolved methods were used to measure total reaction rate constants and steady-state methods were used to determine chemical reaction rate constants. GC-MS was used to tentatively assign the reaction products. 5,6-Disubstituted cyclic α-diimines are singlet oxygen quenchers, but become more effective in polar solvents. A reaction mechanism involving a perepoxide intermediate or transition state leading to a hydroperoxide seems to be a key reaction path for product formation. A replacement of the phenyl substituent for a methyl substituent opens up an additional reaction involving a perepoxide-like exciplex, which increases singlet oxygen quenching of the cyclic α-diimines. The reactivity of 5,6-disubstituted cyclic α-diimines towards singlet oxygen is highly dependent on steric interactions arising from vicinal phenyl rings and from electronic effects. 1,4-Disubstituted acyclic α-diimines are, by comparison, moderate or poor singlet oxygen quenchers. Total rate constants are scarcely dependent on solvent properties, but instead correlate with the Hildebrand parameter. These results are explained in terms of a mechanism involving a dioxetane-like exciplex that gives rise to a charged intermediate leading to products.

Synthesis of a polymer-capped palladium nanoparticles and its application as a reusable catalyst in oxidative coupling reaction of α-hydroxyketones and 1,2-diamines for preparation of pyrazines and quinoxalines

A novel method for the synthesis of pyrazines and quinoxalines has been developed using α-hydroxyketones and 1,2-diamines in the presence of cross-linked poly(4-vinylpyridine)-stabilized Pd(0) nanoparticles, [P4-VP]-PdNPs. The catalyst was easily prepared and characterized using various techniques such as FT-IR and UV–Vis spectroscopy, AAS, TEM, FESEM, EDX analysis and XRD. The results confirm a good dispersion of palladium nanoparticles on the polymer support. The catalyst displayed good catalytic activity when applied to the synthesis of quinoxalines via condensation of α-hydroxyketones with 1,2-diamines. A few pyrazine derivatives and various quinoxalines are prepared via coupling reaction of α-hydroxyketones and 1,2-diamines in high–excellent yields (81–99%) with short reaction times. The quinoxalines products were characterized by FT-IR, 1H and 13C NMR spectroscopy, and the physical properties were compared to the literature values of known compounds. The advantages of the present method over conventional classical methods are rapid and very simple work-up, and the catalyst is reusable many times without a significant loss in its activity.

Synthetic method of quinoxaline heterocyclic compound

The invention provides a synthetic method of a quinoxaline heterocyclic compound. A quinoxaline heterocyclic derivative is prepared through one step by carrying out oxidation and cyclic condensation reaction on benzoin and ortho-diamine under the catalysis of a non-transition metal catalyst. According to the method, low-price and easily-available benzoin is used as a raw material, a water-soluble non-transition metal is used as a catalyst and convenient, economical and safe air is used as a direct oxidant to synthesize a target heterocyclic compound through one step at room temperature or a temperature slightly higher than the room temperature; the reaction condition is simple and mild; and inert gas protection is not needed as the synthesis is carried out in the air. The method is easy to operate, the only byproduct is water, the product is simple and easy to separate and purify, the yield is high, and the reaction condition requirement is relatively low, so that the method is wide in application range and has good research and industrial application prospects.

Iodine-mediated efficient synthesis of 2,3-dihydro-pyrazines

The synthesis of 2,3-dihydro-pyrazines has been developed by an efficient protocol of annulations of 1,2-diketones and ethylenediamine. A variety of 2,3-dihydro-pyrazines were prepared in high yields in the presence of a catalytic amount of iodine.

Synthesis, structures, and DFT study of CuBr based coordination polymers via in situ reduction of copper(II)

This paper describes the one-pot synthesis of two CuBr based coordination polymers, {[Cu(??2-L1)Br]?·1.87H2O}n (1) and {[Cu(??2-L2)Br]?·C4H10O}n (2), where

Design and construction of copper(I) complexes based on flexi-dentate cyclic N2-donor Schiff bases via in situ reduction of copper(II) precursors

Three copper(I) complexes [Cu(μ2-L1)I]n (1), [CuL1(μ-1,1,3-SeCN)]n (2) and [Cu 2(μ2-I)2(L2)2] (3), where L1 = 5,6-diphenyl-2,3-dihydro

Poly(N,N ′-dibromo-N-ethyl-benzene-1,3-disulphonamide) and N,N,N ′,N ′-tetrabromobenzene-1,3- disulphonamide as novel catalysts for synthesis of quinoxaline derivatives

Poly(N,N ′ -dibromo-N-ethyl-benzene-1,3-disulphonamide) [PBBS] and N,N,N ′,N ′ -tetrabromobenzene-1,3- disulphonamide [TBBDA] were used as efficient catalysts for the synthesis of quinoxaline derivatives in excellent yields from 1,2-diamines and 1,2-dicarbonyls under aqueous and solvent-free conditions. [Figure not available: see fulltext.]

YbCl3-catalyzed one-pot synthesis of dihydropyrazines, piperazines, and pyrazines

A simple and efficient synthetic approach to dihydropyrazines via YbCl 3-catalyzed reaction of α-hydroxyketones with diamines under mild conditions was developed. The corresponding 2,3-subsitituted piperazines and pyrazines were obtained through tandem conversion of dihydropyrazines with good yields.

A new catalytic method for eco-friendly synthesis of quinoxalines by zirconium (IV) oxide chloride octahydrate under mild conditions

An environmentally benign catalytic method for efficient synthesis of quinoxaline derivatives via the condensation reaction of 1,2-diamines and 1,2-dicarbonyl compounds using ZrOCl2.8H2O in EtOH as a standard green solvent under mild conditions has been developed. The reusability of the catalyst has been successfully examined without any noticeable loss of its catalytic activity.

Reaction of 2,3-Diphenylpyrazine 1-Oxides with Acetic Anhydride

Some 2,3-diphenylpyrazine 1-oxides were heated with acetic anhydride to give the corresponding 2,3-diacetoxy-2,3-dihydro-5,6-diphenylpyrazines.By X-ray diffraction analysis, the configuration of two acetoxyl groups was determined to be trans.