Thermal decomposition of 2-amino-3-aziridino-1,4-naphthoquinones

The course of the thermal decomposition of various 2-amino-3-substituted aziridino-1,4-naphthoquinones (Ia-g) was investigated. In all the cases, the thermal decomposition gave variable amounts of 2,3-diamino-1,4-naphthoquinone (II) and of substituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxaline-5,10-diones (IIIa-g) with complete stereospecificity. The decomposition of the aziridines Ib,f also gave significative amounts of 2-amino-3-allylamino-1,4-naphthoquinones (IVb,f). In the case of 2-amino-3-(2′-phenyl-3′-ethylaziridino)-1,4-naphthoquinone (Ig), the formation of trans-1-phenyl-1-butene (V), 2-(1-phenylpropyl)-1H-naphtho-imidazole-4,9-dione (VI), 2-phenyl-3-ethyl-3,4,5,10-tetrahydrobenzo[g]quinoxaline-5,10-dione (VII), 2-phenyl-3-ethyl-5,10-dihydrobenzo[g]quinoxaline-5,10-dione (VIII), and a mixture of cis- and trans-4H-2,3,5,6-tetra-hydro-2-phenyl-3-ethyl-5-iminonaphtho[1,2-b]oxazin-6-one (IX) also occurred. Hypotheses concerning the mechanism and the steric course of this reaction are given. The reaction is a general method for the stereospecific synthesis of 2,3-disubstituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxalines.     

Photolysis of 2-dialkylamino-3-methyl-1,4-naphthoquinones

The photolysis of 2-dialkylamino-1,4-naphthoquinones is significantly more efficient when a methyl group is at C³. The quantum yields are 2–6 times greater than for 2-dialkylaminonaphthoquinones lacking a methyl group. 2-Monoalkyl-amino-1,4-naphthoquinones also undergo photochemical dealkylation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2387–2392, October, 1991.     

Solvent effects on the oxidative free radical reactions of 2-amino-1,4-naphthoquinones

Solvent effects on the manganese (III) initiated oxidative free radical reactions of 2-amino-1,4-naphthoquinones are described. This free radical reaction provides a novel method for the synthesis of benzo[f]indole-4,9-diones, benzo[f]indole-2,4,9-triones, benzo[b]carbazole-6,11-diones and benzo[b]acridine-6,11-diones. High chemoselectivity was observed in different solvents.     

Investigation on the isomerization of 2-amino-3-aziridino-1,4-naphthoquinones to benzo[g]quinoxalines

The course of the hydriodic acid-catalysed and iodide-catalysed isomerization of various 2-amino-3-substituted-aziridino-1,4-naphthoquinones (I) to 1,2,3,4,5,10-hexahydrobenzo[g]-quinoxaline-5,10-diones (III) is investigated, and steric aspects of the reaction are also considered. Only in the case of the phenylaziridino derivative (Ie) does hydriodic acid afford direct cyclization to the corresponding benzoquinoxalinedione (IIIe); in all other cases the hydriodides (V) of the cleavage products (II) are obtained, and liberation of the free bases (II) results in cyclization to the corresponding benzoquinoxalinediones (III) when the aziridine ring is monosubstituted or trans disubstituted, with retention of configuration in the latter case. In contrast, the free bases (II) obtained from cis disubstituted (I) are relatively stable and cyclize with excess iodide yielding trans disubstituted (III). Correspondingly, monosubstituted and trans disubstituted I undergo iodide-catalysed isomerization to III whereas cis disubstituted I do not react.     

Thermal conversions of 2-azido-3-piperazino-substituted 1,4-naphthoquinones

Conclusions The 2-azido derivatives which are formed when 2-chloro-3-(4-acylpiperazino)-1,4-naphthoquinones are reacted with NaN₃ in DMF are converted during the reaction to the corresponding 2-amino derivatives and the cyclization products-naphthimidazolediones.2. It is shown that the precursors of the naphthimidazolediones are 1-(3-amino-1,4-naphthoquinonyl-2)-1,4,5,6-tetrahydropyrazines, which are products from dehydrogenation of the piperazine ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2822–2826, December, 1988.     

Synthesis and Transformations of 2-Hydroxy-3-arylazo-1,4-naphthoquinones

A series of 2-hydroxy-3-arylazo-1,4-naphthoquinones were prepared by coupling of 2-hydroxy-1,4-naphthoquinone with aryldiazonium chlorides. The reactivity of the products toward electrophilic and nucleophilic agents was studied. In reaction with o-phenylenediamine they give condensation products, the corresponding benzo[a]phenazines.     

Photolysis of 2-piperidino- and 2-morpholino-3-methoxy-1,4-naphthoquinones

PMR and¹³C NMR spectroscopy was used to establish the structure of the primary products of the photolysis of 2-piperidino- and 2-morpholino-3-methoxy-l, 4-naph-thoquinones. A scheme for the subsequent dark transformations of these compounds is proposed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 709–713, March, 1991.     

Acylation of 2-arylamino-3-chloro-5,8-dihydroxy-1,4-naphthoquinones

2-Arylamino-3-chloro-5,8-dihydroxy-1,4-naphthoquinones reacted with acetic anhydride and benzoyl chloride in pyridine to give in succession the corresponding O-acyl derivatives at both hydroxy groups. The primary acylation products were 8-acyloxy-2-arylamino-3-chloro-5-hydroxy-1,4-naphthoquinones.     

Three different dimerizations of 2-bromo-3-methyl-1,4-naphthoquinones

Three types of dimeric naphthoquinones, which possess structurally diverse skeletons, can be prepared in one step from 2-bromo-3-methyl-1,4-naphthoquinones. 2,2'-Dimeric naphthoquinones were prepared by a one-pot Stille-type reaction via vinylstannanes. Oxepines are formed by unexpected domino reactions via 1,4-dihydroxynaphthalene species. Epoxides are formed by a Michael/Darzens reaction via the o-quinone methides.     

Isomerization of 4-arylamino-1,2-naphthoquinones to 2-arylamino-1,4-naphthoquinones

4-Arylamino-1,2-naphthoquinones isomerize into 2-arylamino-1,4-naphthoquinones upon refluxing in acetic acid. The isomerization follows two routes via intermediate 2-hydroxy-1,4-naphthoquinone and 2-arylamino-1,4-naphthoquinone 4-N-arylimines.     

Revision of the scheme for the formation of heterocyclic quinones upon the photolysis of 3-amino-2-cycloalkylamino-1,4-naphthoquinones

Conclusions The formation of naphthimidazole derivatives in the photolysis of 3-amino- and 3-acetyl-amino-2-cycloalkylamino-1,4-naphthoquinones is the result of the dark intramolecular cyclization of the corresponding 3-aminoenaminoquinones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 694–699, March, 1989.     

Iodinated 1,4-naphthoquinones

Iodination of 5-amino- and 6-amino-1,4-naphthoquinones with I₂ and HIO₃ in aqueous dioxane occurs only at the benzoid ring. Depending on the reaction conditions, either aminoiodo- or aminodiiodonaphthoquinones are produced. Diazotization of these compounds followed by reduction or replacement of the diazo group with iodine affords mono- or polyiodo derivatives of 1,4-naphthoquinone. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1465–1469, June, 2005.     

Intramolecular cyclization of 2-aryl-3-aminoacetyl-1,4-naphthoquinones to 3-benzocoumaranone derivatives

The isomerization of 2-aryl-3-(N-alkyl-N-arylamino)acetyl-1,4-naphthoquinones to 2-(N-alkyl-N-arylamino)-4-aryl-5-hydroxy-6,7-benzocoumaran-3-ones was studied. The structures of the compounds obtained were confirmed by the data from the UV, IR, mass and PMR spectra.Communication 30 from the series Synthesis and Properties of Charge-Transfer Complexes and Self-Complexes; see [1] for communication 29.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 739–745, June, 1979.     

Synthesis of 2-amino(alkylamino)-3-nitro-1,4-naphthoquinones

The reaction of 2-amino(alkylamino)-1,4-naphthoquinones with nitrating mixture in concentrated sulfuric acid leads to the formation of 2-amino(alkylamino)-3-nitro-1,4-naphthoquinones.     

Synthesis and structure of N-substituted 2-amino-3-phenacylidene-3,4-dihydroquinoxalines

N-Substituted 2-imino-5-aryl-2,3-dihydro-3-furanones react with o-phenylenediamine to form N-substituted 2-amino-3-phenacylidene-3,4-dihydroquinoxalines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 528–531, April, 1989.     

Synthesis of 1H-naphth[2,3-d]imidazole-4,9-diones by acid catalyzed cyclization of 2-Acylamino-3-amino-1,4-naphthoquinones

The conversion of 2-acylamino-3-amino-1,4-naphthoquinones (II) to the corresponding 2-substituted 1H-naphth[2,3-d]imidazole-4,9-diones (I) under both alkaline and acid catalyzed conditions has been effected and the results compared. Treatment of 3-(4′-chlorobutanonyl-amino)-3-amino-1,4-naphthoquinone (He) with aqueous ethanolic sodium hydroxide solution gives 1,2-butanonaphth[2,3-d]imidazole-4,9-dione (V); whereas, treatment of lie with refluxing formic acid gave 2-(4′-chlorobutyl)-1H-naphth[2,3-d]imidazole-4,9-dione. Treatment of 2-substi-tuted 1H-naphth[2,3-d]imidazole-4,5-diones in DMF with alkyl halides in the presence of potassium carbonate affords the expected 1,2-disubstituted naphth[2,3-d]imidazole-4,9-diones (VI). The spectral properties of I, II, V and VI as well as those of some 2-acylamino-3-chloro-1,4-naphthoquinones IV are discussed.     

5-arylethynyl-1,4-naphthoquinones

Conclusions The syntheses of a series of 5-arylethynyl-1,4-naphthoquinones were carried out by the reaction of 5-iodonaphthoquinone with substituted cuprous acetylides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2561–2565, November, 1984.