V. P. Vetchinov

Experimental and quantum chemical study of the reactions of 1,10-anthraquinones with alcohols and amines

Abstract The primary stage of the reaction between 9-aryloxy-1,10-anthraquinones and methanol is the nucleophilic 1,4-addition which gives rise to the adduct, corresponding to 1-hydroxy-9-methoxy-9-aryloxy-10-anthrone. The reaction of 9-aryloxy-1,10-anthraquinones with the primary aliphatic and aromatic amines results in the formation of 9-alkyl(aryl)amino-1,10-anthraquinones that are in a tautomeric equilibrium with 1-hydroxy-9,10-anthraquinone-9-alkyl(aryl)imines. The quantum chemical calculations of the enthalpy of 9-amine-1,10-anthraquinone isomerization are in agreement with the experimentally recorded influence on the tautomeric equilibrium of the nature of amine, solvent, and substituent in the anthraquinone nucleus. The data of quantum chemical calculations confirm the addition-elimination mechanism of the reaction of 1,10-anthraquinones with amines.

Reactions ofN-pentafluorophenylcarbonimidoyl dichloride with aromatic hydrocarbons in the presence of aluminum chloride

N-Pentafluorophenylcarbonimidoyl dichloride reacts with aromatic hydrocarbons (benzene, toluene, xylenes, and mesitylene) in the presence of AlCl3 to give stableN-pentafluorophenylbenzimidoyl chlorides, which can further react with aromatic hydrocarbons to give azomethine derivatives. An increase in the number of methyl groups in the molecule of a hydrocarbon favors the reaction.

Photolysis of 2-dialkylamino-3-amino(or alkylamino)- 1,4-naphthoquinones

Using1H and13C NMR spectroscopy, naphthodihydroimidazolediols were identified as the primary products of photolysis of 2-dialkylamino-3-amino(alkylamino)-1,4-naphthoquinones. Their further non-photochemical (≪thermal≫) transformations depend on their structure and on the photolysis conditions.

The products of the photolysis of 2-(4-alkyI(or phenyl)piperazino)-3-amino-1,4-naphthoquinones, their structures and subsequent thermal transformations

Photolysis of 2-(4-alkyI(phenyl)piperazino)-3-amino-1,4-naphthoquinones affords 2-alkyl (phenyl)-1,2,3,4,12,12a-hexahydronaphtho[2′,3′∶4,5]imidazo[1,2-a]pyrazine-6,11-diols which recyclize at elevated temperatures to yield 1,2,3,4-tetrahydro-13-alkyl(phenyl)-3,1-(iminoethano) benzo[g]quinoxaline-5,10-diols. The latter are oxidated with atmospheric oxygen to the corresponding diones. On the basis of deuterium exchange data a mechanism for the recyclization is proposed.

Photochemical synthesis of 2-amino-1-hydroxy-9,10-anthraquinone-9-alkyl(aryl)imines

Irradiation of a mixture of 1-aryloxy-2-amino-9,10-anthraquinone and amines in benzene results in formation of the derivatives of 2-amino-1-hydroxy-9,10-anthraquinone-9-alkyl(aryl)imines in a high yield. 2-Amino-1-hydroxy-9,10-anthraquinone-9-aikylimines were shown by13C and15N NMR to exist predominantly in the enaminoquinoid form whereas 2-amino-1-hydroxy-9,10-anthraquinone-9-arylimines exist in the oxyimine form. Sunlight irradiation of the derivatives of 2-benzoylamino-9,10-anthraqumone-9-alkylimines results in formation of the photocyclization products — 4-benzoylaminoanthra-[9,1-d,e]-1,3-oxasinones-7.