Reactions of 1,4-naphthoquinone and 5-hydroxy-1,4-naphthoquinone with ninhydrin

Russian Chemical Bulletin - 1,4-Naphthoquinone and 5-hydroxy-1,4-naphthoquinone react with ninhydrin to give 2-(2-hydroxy-1,3-dioxo-2,3-dihydro-1H-inden-2-yl)naphthalene-1,4-dione and 8-hydroxy-...     

Reactions of amines with bischloromethyltetramethyldisiloxane and its derivatives

Summary The reaction of bischloromethyltetramethyldisiloxane and its derivatives with mono- and di-amines was investigated, and it was shown that reaction proceeds with formation of cyclic compounds irrespective of the groups attached to the silicon atoms. Six new compounds were synthesized.     

Synthesis of 2-aminopentafluoro-1,4-naphthoquinone derivatives

Potential biologically active derivatives of 2-aminopentafluoro-1,4-naphthoquinone modified at the amino group were synthesized in 32–96% yield by reactions of hexafluoro-1,4-naphthoquinone with nitrogen-centered nucleophiles.     

由2-羟基-1,4-萘醌合成2-乙氧基-1,4-萘醌

由2-羟基-1;4-萘醌合成2-乙氧基-1;4-萘醌;乙氧基萘醌; 羟基萘醌; 乙醇; 硝酸; 回流     

Electronic transitions in 1,4-naphthoquinone derivatives

Single electronic transitions in 1,4-naphthoquinone and seven of its derivatives substituted in the quinoid system have been theoretically studied semi-empirical SCF MO CI calculations, in the frame of π and all valence electron (AVE) approximations. Dipole electrostatic contributions to the shifts originating from the solvent have been calculated and the local nature of the most significant transitions has been analyzed. The results agree satisfactorily with experiment, showing the effects of the substituents, which in some cases are underestimated.     

Cyclocondensation of 5-ethynyl-1,4-naphthoquinone derivatives with hydrazine

Condensation of 5-arylethynyl-3-diethylaminonaphthoquinones with NH₂NH₂ afford 3-benzyl-9-diethylaminobenzo[de]cinnolin-7-ones. The substituents in the phenyl ring have a pronounced effect on the reaction time and the yields of benzocinnolinones and by-products. The replacement of the arylethynyl substituent in the starting naphthoquinone by the 3-hydroxyalk-1-ynyl group leads to a change in the direction of cyclization resulting in substituted naphtho[1,8-cd]-1,2-diazepin-8-ones as condensation products.     

Reactions of 5-oxo-1-phenylpyrrolidine-3-carbohydrazides with 1,4-naphthoquinone derivatives and the properties of the obtained products

N′-(4-Oxo-1,4-dihydronaphthalen-1-ylidene)-1-phenyl-5-oxopyrrolidine-3-carbohydrazides and N′-(3-methyl-4-oxo-1,4-dihydronaphthalen-1-ylidene)-1-phenyl-5-oxopyrrolidine-3-carbohydrazides were synthesized by reactions of 5-oxo-1-phenylpyrrolidine-3-carbohydrazides with 1,4-naphthoquinone or 2-methyl-1,4-naphthoquinone. The alkylated analogues of the above products were obtained using ethyl iodide. The interaction of 5-oxo-1-phenylpyrrolidine-3-carbohydrazides with 2,3-dichloro-1,4-naphthoquinone was followed by formation of N′-(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-yl)-1-phenyl-5-oxopyrrolidine-3-carbohydrazides. All these compounds were characterized using ¹H, ¹³C NMR, IR and mass spectra. Some of the new compounds were tested for the antimicrobial and antifungal activity.     

Synthesis and spectral properties of 1,4-naphthoquinone sulfanyl derivatives

Reactions of 2,3-dichloro-1,4-naphthoquinone with hexadecanethiol and other alkanethiols in ethanol in the presence of sodium carbonate afforded new symmetric and unsymmetrical sulfanylnaphthoquinone dyes.     

Studies on the reactivity of aryliodonium ylides of 2-hydroxy-1,4-naphthoquinone: reactions with amines

Aryliodonium ylides of 2-hydroxy-1,4-naphthoquinone react with amines in refluxing dichloromethane to afford good yields of indanedione 2-carboxamides 5, through a ring-contraction and alpha,alpha'-dioxoketene formation reaction. These amides exist in solution in an unusual enol-amide form. In contrast, the same reactants in a copper-catalyzed reaction afford arylamines and 3-iodo-4-hydroxy-1,2-naphthoquinone.     

Diels-Alder Reactions of 5,8-Ethano-5,8-dihydro-1,4-naphthoquinone with Cyclic Dienes

Diels-Alder cycloadditions of 1,3-cyclohexadiene and cyclopentadiene to π -facially dissymmetric 5,8-ethano-5,8-dihydro-1,4-naphtboquinone (1) were examined. The stereochemical outcome of the reactions, determined by a combination of chemical and spectral methods, indicates that addition of cyclic dienes to 1 occurs preferentially at the face syn to the etheno-bridge of 1. Cycloadducts 7a/7b and 8a/8b obtained from Diels-Alder reactions of 1 with cyclopentadiene and 1,3-cyclohexadiene undergo [2+2]-photocyclization to give caged compounds 9a/9b and 10a/10b , respectively. Stereoselective reduction of the enedione double bond in 7a/7b and 8a/8b with aqueous TiCl₃ in acetone affords cis-bis-bicyclic ring-fused 1,4-cyclo-hexadiones 11a/11b , and 12a/12b , respectively.     

Reaction of 2-mercaptobenzimida(thia)zole with 1,4-naphthoquinone and its oxide

The reaction of 2-mercaptobenzimida(thia)zole with 1,4-naphthoquinone proceeds as nucleophilic 1,4-addition to give the corresponding thioethers. The reaction of 1,4-naphthoquinone oxide with 2-mercaptobenzimidazole leads to benzimidazonaphthothiazole, while the reaction of the oxide with 2-mercaptobenzothiazole leads to a thioether as a consequence of the addition of the mercapto-substituted heterocycle at the oxide ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 121–124, January, 1992.     

Reactions of Substituted Indoles with 2,3-Dichloro-1,4-naphthoquinone and Electrochemical Properties of Some 2,3-Substituted 1,4-Naphthoquinones

Russian Journal of Organic Chemistry - The reactions of 2,3-dichloro-1,4-naphthoquinone with some indoles and thiols were investigated. The resulting nucleophilic substitution products were...     

Novel 2-amino-3-(2,4-dinitrophenylamino) derivatives of 1,4-naphthoquinone

The strong electron withdrawing nature of a 2,4-dinitrophenylamino group when attached to a chloro-naphthoquinone enhances the displacement of the chlorine atom by various aliphatic, cyclic and aromatic amines. A new series of 2-amino-3-(2,4-dinitrophenylamino) derivatives of 1,4-naphthoquinone were prepared. Three absorption maxima in the UV-vis spectra were typical, including one at 430-550 nm assigned to a CT transition.     

Synthesis and properties of fused tetracyclic derivatives of 1,4-naphthoquinone thioglycosides

A series of 1,4-naphthoquinone O-acetylthioglycosides have been synthesized by the condensation of fully O-acetylated derivatives of 1-thio-d-xylose, 1-thio-L-arabinose, 1-thio-d-galactose, 1-thio-d-mannose, and 1-thiomaltose with 3-chloro-2-methoxy-1,4-naphtho-quinone. Their deacetylation with MeONa/MeOH proceeded with simultaneous heterocyclization to yield linear carbohydrate-containing tetracyclic quinones. Tetracycles with trans junction of the carbohydrate and quinone rings are poorly soluble in water and organic solvents.     

Vicinal acetylenic derivatives of 2-amino-1,4-naphthoquinone as key precursors of heterocyclic quinones

The Pd-catalyzed reaction between 3-acetylamino-2-bromo-1,4-naphthoquinones and Cu^I acetylides prepared in situ gave 3-acetylamino-2-alkynyl-1,4-naphthoquinones, which were transformed into benz[f]indole-4,9-dione and benzo[g]quinoline-5,10-dione derivatives.     

Photolysis of 2-amino- and 2-methylamino-1,4-naphthoquinone

Pyrex-filtered sunlight irradiation of solutions of 2-amino-1,4-naphthoquinone unexpectedly failed to produce cyclobutane dimers. Irradiation in acetic anhydride led to the formation of the trimeric 6-[3'-amino-2'-(1,4-naphthoquinonyl)]-dibenzo[b,h]carbazole-5,13:7,12-diquinone as well as 3,3'-diaraino-2,2'-bi-1,4-naphthoquinonyl and diben=zo[b,h]carbazole-5,13;7,12-diquinone. Similar treatment of 2-methyl=amino-1,4-naphthoquinone afforded 6-[3'-methylamino-2'-(1,4-naphthoqui=nonyl)]-dibenzo[b,h]carbazole-5,13:7,12-diquinone and 6-methyl-dibenzo=[b,h]carbazole-5,13:7,12-diquinone.     

Synthesis of 2-alkoxy 1,4-naphthoquinone derivatives as antiplatelet,antiinflammatory, and antiallergic agents

In our continuing search for novel antiplatelet, antiallergic, and antiinflammatory agents, 2-alkoxy derivatives of 1,4-naphthoquinone were prepared. Some of these compounds showed significant antiplatelet, antiallergic, and antiinflammatory activities. Among them, 2-propoxy-1,4-naphthoquinone and 2-butoxy-1,4-naphthoquinone exhibited potent inhibitory effect on neutrophil superoxide anion formation. These two compounds are worthy of further exploration.