V. N. Komissarov

New method for the synthesis of β-tropolones : Structures of condensation products of o-quinones with 2-methylquinolines and the mechanism of their formation

A new method was developed for the synthesis of functionalized β-tropolones based on acid-catalyzed condensation of 2-methylquinoline derivatives with 3,5-di(tert-butyl)-1,2-benzoquinone and 4,6-di(tert-butyl)-3-nitro-1,2-benzoquinone (14). The mechanism of the multistep reaction giving rise to β-tropolones and their tautomerism were studied by quantum chemical methods (DFT B3LYP/6-31G**). The reaction of 2-methylquinoline derivatives containing the tertiary amino group at position 4 with quinone 14 is accompanied by the formation of derivatives of a new heterocyclic system, viz., 4,6-dioxo-2-azabicyclo[3.3.0]octa-2,7-diene N-oxide. The molecular and crystal structures of two 5,7-di(tert-butyl)-3-hydroxy-2-(quinolin-2-yl)tropolones and two dioxoazabicyclooctadiene N-oxides, as well as of the preparatively isolated intermediate of the first condensation step and of the by-product of the reaction were established by X-ray diffraction.

Perimidmespirocyclohexadienones - a Novel Photo and Thermochromic System

Abstract A new class of photochromic compounds, derivatives of 2,3-dihydro-2-spiro-4′-(2′,6′-di-tert-butylcyclohexadienon-2′,5′- one) erimidine is described and their photochromic and thermochromic rearrangements described.

Synthesis and cytotoxic activity of [benzo[b][1,4]oxazepino[7,6,5-de]quinolin-2-yl]-1,3-tropolones

We describe the synthesis of previously unknown halogenated derivatives of 2-(benzo[b][1,4]oxazepino[7,6,5-de]quinolin-2-yl)-1,3-tropolone. The MTT colorimetric assay was used to detect anticancer activity and inhibition of human epidermoid carcinoma (KB human epithelial carcinoma cell line) growth by 9,11-di(tert-butyl)-5-chloro-2,4-dimethyl-7Н-enzo[b][1,4]oxazepino[7,6,5-de]quinoline at IC50 93.7 μg/ml, and human breast carcinoma (MCF-7 cell line) growth by 2-[7-acetyl-9,11-di(tert-butyl)-5-chloro-4-methylbenzo[b][1,4]-oxazepino[7,6,5-de]quinolin-2-yl]-5,6,7-trichloro-1,3-tropolone at IC50 12.96 μg/ml.

2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties

Summary A series of derivatives of 2-hetaryl-1,3-tropolone (β-tropolone) was prepared by the acid-catalyzed reaction of 2-methylbenzoxazoles, 2-methylbenzothiazoles and 2,3,3-trimethylindoline with 3,4,5,6-tetrachloro-1,2-benzoquinone. The molecular structures of the three representative compounds were determined by X-ray crystallography. In crystal and (as shown by the DFT PBE0/6-311+G** calculations) in solution, 2-hetaryl-4,5,6,7-tetrachloro- and 2-hetaryl-5,6,7-trichloro-1,3-tropolones exist in the NH-tautomeric form with a strong resonance-assisted intramolecular N–H···O hydrogen bond. The mechanism of the formation of 1,3-tropolones in the reaction of methylene-active five-membered heterocycles with o-chloranil in acetic acid solution has been studied using density functional theory (DFT) methods. The reaction of 2-(2-benzoxa(thia)zolyl)-5,6,7-trichloro(4,5,6,7-tetrachloro)-1,3-tropolones with alcohols leads to the contraction of the seven-membered tropone ring with the formation of 2-(2-benzoxa(thia)zolyl)-6-alkoxycarbonylphenols. The molecular structure of 2-(2-ethoxycarbonyl-6-hydroxy-3,4,5-trichlorophenyl)benzoxazole has been determined by X-ray diffraction. 2-(2-Benzoxa(thia)zolyl)-6-alkoxycarbonylphenols display intense green fluorescence with anomalous Stokes shifts caused by the excited state intramolecular proton transfer (ESIPT) effects.

3,5-Di-tert-butyl-1,2-benzoquinone in the synthesis of quinolino[4,5-bc][1,5]benzoxazepines, aminophenols, and phenoxazines

Reaction of 3,5-di-tert-butyl-1,2-benzoquinone with 5-amino-4-chloroquinolines gave derivatives of a new fused heterocyclic system, substituted quinolino[4,5-bc][1,5]benzoxazepines. The molecular structure of 9,11-di-tert-butyl-2,4,6-trimethyl-7H-quinolino[4,5-bc][1,5]benzoxazepine was determined by X-ray analysis. 3,5-Di-tert-butyl-1,2-benzoquinone reacted with o-nitro-, o-acyl-, and o-methoxycarbonylanilines and some amino-substituted nitrogen-containing heterocycles to form the corresponding sterically hindered N-aryl-(hetaryl)-o-aminophenols. Di-tert-butyl-substituted phenoxazines were obtained as a result of thermal cyclization of intermediately formed quinone imines.

Synthesis and some conversions of N-substituted benzimidazole-2-sulfonic acids

A series of N-substituted benzimidazole-2-sulfonic acids was synthesized in good yield by the N-alkylation of benzimidazole-2-sulfonic acids by alkylation with simple and functionalized alkylating agents under mild conditions. The corresponding N-substituted benzimidazolones and also primary, secondary, and tertiary amines were obtained by the action on the obtained compounds of alkali, ammonia, ammonium acetate, and amines.

Synthesis and structure of 3-arylamino-2-(quinolin-2-yl)tropones

A reaction of substituted 2-(quinolin-2-yl)-1,3-tropolones with POCl3 leads to the new3-chloro-2-(quinolin-2-yl)tropone derivatives. New 2-(4-arylaminoquinolin-2-yl)-3-aryl-aminocyclohepta-2,4,6-trien-1-ones and 2-[4-morpholino(piperidino)quinolin-2-yl]-3-aryl-aminocyclohepta-2,4,6-trien-1-ones were obtained by nucleophilic substitution reaction of the halogen atom in 2-(4-chloroquinolin-2-yl)-3-chlorotropones and 3-chloro-2-[4-morpholino-(piperidino)quinolin-2-yl]tropones. Molecular structures of 3-chloro-2-(quinolin-2-yl)tropone and 3-arylamino-2-(quinolin-2-yl)tropone were established by X-ray diffraction analysis. Energy and structural characteristics of isomers of 3-arylamino-2-(quinolin-2-yl)tropones in the gas phase and in solution were calculated by the density functional theory method (PBE0/6-31G**).

Synthesis and structure of heterocyclic derivatives of pyran-2-ones based on the dimer of 4,6-di(tert-butyl)-3-hydroxy-1,2-benzoquinone

Acid-catalyzed reaction of 6,10a-dihydroxy-3,4a,7,9-tetra(tert-butyl)-1,2,4a,10a-tetrahydrodibenzo-[b,e][1,4]dioxine-1,2-dione with 2-methylquinoline derivatives led to the formation of a previously unknown system 6-[(Z)-2-(quinolin-2-yl)-1-hydroxyethen-1-yl]pyran-2-one. The molecular structure of 3,5-di(tert-butyl)-6-[(Z)-2-(7,8-dimethyl-4-chloroquinolin-2-yl)-1-hydroxyvinyl]pyran-2-one was established by XRD method; the energy and structural characteristics of its isomers in the gas phase and in a polar solvent were calculated by quantumchemical methods (B3LYP/6-31G**).

Synthesis and structure of 2,2′-spirobi(1,3-benzodioxole) derivative prepared from 3,5-di(tert-butyl)-1,2-benzoquinone

Abstract3,5-Di(tert-butyl)-1,2-benzoquinone reacted with 1,2,3-trimethylbenzimidazolium iodide led to the formation of 2,2′-spirobi[4,6-di(tert-butyl)-1,3-benzodioxole]. The reaction mechanism was suggested. The structure of 2,2′-spirobi[4,6-di(tert-butyl)-1,3-benzodioxole] was established by means of X-ray diffraction analysis.

Synthesis and structure of new 2-(2-quinolyl)-1,3-tropolone derivatives

Abstract4,6-Di-tert-butyl-3-nitro-1,2-benzoquinone reacts with substituted 2-methylquinolines to give the corresponding 2-(2-quinolyl)-4-nitro-1,3-tropolones and 2-(2-quinolyl)-1,3-tropolones.