Phenazine 5,10-dioxide

The generation of other heteroq cles from Bfx and Fx has been the subject of exhaustive investigation. The most important transformation of Bfx to other heterocycles has been described by Haddadin and Issidorides, and is known as the Beirut reaction . This reaction involves a condensation between adequate substituted Bfx and alkene-type substructure synthons, particularly enamine and enolate nucleophiles. The Beirut reaction has been employed to prepare quinoxaline 1,4-dioxides [41], phenazine 5,10-dioxides (see Chap. Quinoxahne 1,4-dioxide and Phenazine 5,10-dioxide. Chemistry and Biology ), 1-hydroxybenzimidazole 3-oxides or benzimidazole 1,3-dioxides, when nitroalkanes have been used as enolate-producer reagent [42], and benzo[e] [ 1,2,4]triazine 1,4-dioxides when Bfx reacts with sodium cyan-amide [43-46] (Fig. 4). 

Benzofuroxan 84 forms substituted phenazine 5,10-dioxides 83 and 85 with the corresponding dihydroxybenzenes <2000H(53)2151> or 2-hydroxynaphthoic-3-acids in basic condition in good yields (Scheme 19) <2002BML415>. 

Hasegawa and co-workers illustrated the syntheses of substituted phenazine-5,10-dioxides 236 by a dehydrative condensation between benzofuroxan 234 and dihydroxybenzene derivatives 235 catalyzed by molecular sieves at room temperature <00H2151>. 

Many quinoxaline 1,4-dioxides have been prepared by the Beirut reaction (Section 8.03.10). Phenazine 5,10-dioxides are prepared by the Beirut reaction using hydroquinone (Section 8.03.10), and they can be also synthesized by treatment of o-nitroanilines with dihydroxybenzenes (Equation 32) <1995M1217>. 

A poly(phenylquinoxaline) was prepared for electroluminescence applications <1996SM(76)105>. Crystallization of solution donor-acceptor complexes of 2,3-dimethylquinoxaline 1,4-dioxide or phenazine 5,10-dioxide with TCNE afforded two-component solids containing weakly bound 1-D donor-acceptor arrays <1997TL7665>. A pyrazine ladder polymer was constructed from two different pyrazine units, as an optical device <1999JA8783>. The new electron-deficient macrocycle tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazine was prepared from l,2-di(2-pyridyl)ethanedione and 2,3-diaminomaleonitrile for a study of its electrochemical properties <2004IC8626>. 

Phenazine 5,10-dioxide Cr(C104)3L2H20 [Cr(CI04)3]2L-12H20 13,14... 

Quinoxaline 1,4-Dioxide and Phenazine 5,10-Dioxide. Chemistry and Biology... 

Abstract Since the beginning of the past century, quinoxaline 1,4-dioxide and phenazine 5,10-dioxide derivatives have been known to be potent bioactive compounds. Maybe the... 

Since the beginning of the past century, quinoxaline 1,4-dioxide (QDO) and phenazine 5,10-dioxide (PDO) derivatives have been described as interesting biological active compounds reminding its interest in medicinal chemistry until now. Formally, these compounds are [l,4]diazine 1,4-dioxide derivatives, and specifically QDO should be named as benzo[fc][l,4]diazine 1,4-dioxide and PDO as dibenzo[fc,e][l,4]diazine 5,10-dioxide, however, the common trivial name of the base heterocycle, quinoxaline (Qx) and phenazine... 

In chapter five Gonzalez et al. presents a comprehensive review on the chemistry and biology of the quinoxaline 1,4-dioxide and phenazine 5,10-dioxide type molecules. They also discuss the mode of action, structure-activity studies and other relevant chemical and biological properties for such molecules. 

The electrochemical properties of phenazine 5,10-dioxides have been studied by cyclic voltammetry in acetonitrile solutions in the presence of acids. ... 

Phenazine 5,10-Dioxide The crude product was dissolved in benzene and a warm solution of MCPBA (3.45 g, 0.02 mol) in benzene was added to it. The mixture was either left to stand at rt or refluxed for B h (see table above). The solution was extracted with 10% aq Na SOj followed by 10% aq NaHCOj and dried. Evaporation of the benzene gave a dark red solid which was treated with 10% aq NaOH. The resulting blue solution was acidified with HOAc to afford the product as a bright red solid. Recrystallization from MeOH/CHCIj or separation by column chromatography (silica gel) yielded the pure product. 

Phenazine-2-ol 5,10-dioxides can be formed by reaction of phenolate anions 2 with benzofuroxans.The intermediate o-quinoid product is stabilized through elimination of water to yield the phenazine-2-ol 5,10-dioxide 3. When phenols are used, phenazine 5,10-dioxides are formed in high yields and under mild reaction conditions. The reaction mechanism and the influence of the substitution pattern on the reaction course have been reported. 

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