L. V. Belousova

Dehydration Rearrangements of Derivatives of Methylenedihydrobenzofuran - a New Path to Substituted Benzofurans

When heated with acidic agents derivatives of 3-amino-2-(hydroxydialkylmethyl)methylene-2,3-dihydrobenzofuran undergo rapid dehydration and rearrangement to substituted 2-alkenyl-3-aminobenzofurans.

Reactions of 2-methylindole with morpholinals of substituted salicylaldehydes

Fusion of 2-methylindole with morphinals of substituted salicylaldehydes (in a ratio of 1 : 1) afforded 3-[(2-hydroxyaryl)morpholinomethyl]-2-methylindoles as normal products of the Mannich reaction. In some cases, the reactions with an excess of 2-methylindole resulted in unusual condensation accompanied by the replacement of the OH group by the morpholino group to form bis(2-methylindol-3-yl)(2-morpholinoaryl)methanes.

Synthesis, structure, and properties of new spirooxindolodibenzodiazepine derivatives

An acid-catalyzed reaction of 3-(2-aminophenylamino)-5,5-dimethylcyclohexen-1-one with isatines leads to the formation of the earlier undescribed 3,3-dimethyl-2,3,4,5,10,11-hexahydrospiro[1H-dibenzo[b,e][1,4]diazepine-11,3′-2H-indole]-1,2′-dione derivatives (6). Spiranes 6 upon heating undergo auto-redox rearrangement with disintegration to 3,3-dimethyl-1,2,3,4-tetrahydrophenazine and the corresponding oxindole. Crystals of four derivatives of compound 6 were studied by X-ray diffraction method.

Opianic Acid in the Synthesis of Benzimidazole Derivatives

Heating an equimolar mixture of opianic acid and o-phenylenediamine in MeOH or EtOH produced 2-(2-carboxy-3,4-dimethoxyphenyl)benzimidazole, which was readily dehydrated in refluxing acetic or propionic anhydride to 11H-1,2-dimethoxyisoindolo[2,3-a]benzimidazol-11-one. Analogous reactions were carried out with 4,5-dichloro-o-phenylenediamine.

Acid-catalyzed reactions of alloxan with compounds containing an activated alkyl group

Condensations of alloxan with 2-methylquinoline, 2,6-dimethyl-5-nitroquinoline, and 1-methylisoquinoline were carried out under acidic conditions. Analogous reactions of alloxan with linear structures containing alkyl groups σ,π-conjugated with C=N fragments were also studied.

Reactions of 3,5-di- tert -butyl-1,2-benzoquinone with mercapto carboxylic acids

Heating of an equimolar mixture of 3,5-di-tert-butyl-1,2-benzoquinone with thiosalicylic acid led to 2-[(4,6-di-tert-butyl-2,3-dihydroxyphenyl)thio]benzoic acid. In the case of β-mercaptopropionic acid, 2-[(4,6-di-tert-butyl-2,3-dihydroxyphenyl)thio]propionic acid was formed, which upon reflux in Ac2O was converted to 6,8-di-tert-butyl-9-hydroxy-3,4-dihydro-2H-1,5benzoxathiepin-2-one.

One-pot synthesis of cotarnine 1-alkynyl derivatives

Cotarnine chloride reacts with terminal acetylenes with short-time heating in acetonitrile in the presence of the catalytic system CuI—morpholine to form cotarnine 1-alkynyl derivatives.

Ring-ring isomerization in the series of N-(carbamoyl)-1-aryl-2,3,4,5,6,7-hexahydro-3-hydroxy-6,6-dimethyl-2,4-dioxo-1H-indole-3-carboxamides

N-(Carbamoyl)-1-aryl-2,3,4,5,6,7-hexahydro-3-hydroxy-6,6-dimethyl-2,4-dioxo-1H-indole-3-carboxamides upon dissolution in DMSO or DMF undergo a reversible isomerization to 5-(2-arylamino-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-5-hydroxypyrimidine-2,4,6(1H,3H,5H)-triones.

Reactions of 4-morpholino-1,2-naphthoquinone with enamines ando-phenylenediamine

The reactions of 4-morpholino-1,2-naphthoquinone with enamines, cyclohexanone derivatives, afford 7a-amino-5-morpholinohexahydrobenzo[b]naphtho[1,2][1,4]dioxines, while the reaction witho-phenylenediamine yields 5-morpholinobenzo[a]phenazine.