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A N Maslivets - One of the best experts on this subject based on the ideXlab platform.

  • five membered 2 3 dioxo heterocycles xci reaction of 3 aroyl 1h pyrrolo 2 1 c 1 4 benzoxazine 1 2 4 triones with dimedone crystalline and molecular structure of 3 benzoyl 4 hydroxy 1 2 hydroxyphenyl 6 6 dimethyl 6 7 dihydrospiro 1 benzofuran 3 2 pyrr
    Russian Journal of Organic Chemistry, 2013
    Co-Authors: N M Tutynina, N. L. Racheva, V A Maslivets, A N Maslivets

    3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with 5,5-dimethylcyclohexane-1,3-dione to give 3′-aroyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-6,7-dihydrospiro[1-benzofuran-3,2′-Pyrrole]-2,4,5′(1′H,5H)-triones. The crystalline and molecular structures of 3′-benzoyl-4′-hydroxy-1′-(2-hydroxyphenyl)-6,6-dimethyl-6,7-dihydrospiro[1-benzofuran-3,2′-Pyrrole]-2,4,5′(1′H,5H)-trione were determined by X-ray analysis.

  • synthesis of dispiro hetero analogs of pyrrolizidine alkaloids
    Russian Journal of Organic Chemistry, 2012
    Co-Authors: V. V. Konovalova, Yurii V Shklyaev, A N Maslivets

    Reactions of spiro heterocyclic enamines with 1H-Pyrrole-2,3-diones, including those fused at the N–C bond to nitrogen-containing heterocycles, were not studied. We have found that 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones Ia and Ib react with an equimolar amount of 2′,5′,5′-trimethyl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-one (II) (which may be regarded as potential 1,3-C,N-binucleophile) in boiling anhydrous benzene (reaction time 2–5 min, until bright violet color typical of the initial pyrrolobenzoxazinetriones disappeared) to give 3′′-aroyl-4′′-hydroxy-1′′-(2-hydroxyphenyl)-3′,3′-dimethyl-2′,3′-dihydrodispiro[naphthalene-1,1′-pyrrolizine-6′,2′′-Pyrrole]-4,5′,5′′(1′′H)-triones IIIa and IIIb in almost quantitative yield. The spectral parameters of compounds IIIa and IIIb are very similar to those found for model ethyl 4-benzoyl-3-hydroxy-1-(2-hydroxyphenyl)-8-methyl-2,6-dioxo-1,7-diazaspiro[4.4]nona-3,8-diene-9-carboxylate whose structure was proved by X-ray analysis [1]. Presumably, the first step is addition of the activated β-CH group in the enamino tautomer of II at the C atom in Ia or Ib, followed by closure of Pyrrole ring via intramolecular attack by the amino group of the enamine fragment on the lactone carbonyl carbon atom in the oxazine ring and opening of the latter at the C–O bond, as was reported by us previously for the reaction of pyrrolobenzoxazinetriones with 1-methyl3,4-dihydroisoquinolines [2]. The described reaction is an example of regioselective synthesis of previously inaccessible dispiro heterocyclic system with various substituents in several positions of both heterocyclic fragments. The products may be regarded as dispiro heterocyclic analogs of pyrrolizidine alkaloids [3]. 4′′-Hydroxy-1′′-(2-hydroxyphenyl)-3′,3′-dimethyl-3′′-(4-methylbenzoyl)-2′,3′-dihydrodispiro[naph-

  • five membered 2 3 dioxo heterocycles liii reaction of 3 aroyl 1h pyrrolo 2 1 c 1 4 benzoxazine 1 2 4 triones with substituted 1 3 3 trimethyl 3 4 dihydroisoquinolines a new approach to 13 aza analogs of steroids
    Russian Journal of Organic Chemistry, 2007
    Co-Authors: N. L. Racheva, Yurii V Shklyaev, Yu S Rozhkova, A N Maslivets

    3-Aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones reacted with substituted 1,3,3-trimethyl-3,4-dihydroisoquinolines to give the corresponding 3-aroyl-4-hydroxy-1-(2-hydroxyphenyl)-5′,5′-dimethyl-5′,6′-dihydro-1H-spiro[Pyrrole-2,2′-pyrrolo[2,1-a]isoquinoline]-3′,5-diones. 7′,8′-Benzo derivatives of the latter may be regarded as 13-azagonane analogs having a spiro-fused Pyrrole ring at C16.

N. L. Racheva - One of the best experts on this subject based on the ideXlab platform.

Yunqi Liu - One of the best experts on this subject based on the ideXlab platform.

Yasuyuki Kita - One of the best experts on this subject based on the ideXlab platform.

Alexander F. Khlebnikov - One of the best experts on this subject based on the ideXlab platform.

  • 1 2h azirine 2 carbonyl benzotriazoles building blocks for the synthesis of Pyrrole containing heterocycles
    Organic and Biomolecular Chemistry, 2020
    Co-Authors: Ekaterina E. Galenko, Mikhail S. Novikov, Vladimir A Bodunov, Firuza M Shakirova, Alexander F. Khlebnikov

    A one-pot method was developed for the preparation of 2H-azirine-2-carbonylbenzotriazoles, formed by the reaction of benzotriazole with 2H-azirine-2-carbonyl chlorides, which were generated by the Fe(ii)-catalyzed isomerization of 5-chloroisoxazoles. The Co(ii)-catalyzed reaction of 2H-azirine-2-carbonylbenzotriazoles with 1,3-diketones provides 2-((benzotriazol-1-yl)carbonyl)Pyrroles in moderate to good yields. Base-promoted annulations of 2-((benzotriazol-1-yl)carbonyl)Pyrroles with aldehydes, ketones, isocyanates and isothiocyanates afford various substituted pyrrolo[1,2-c]oxazole and 1H-pyrrolo[1,2-c]imidazole derivatives in moderate to high yields. The 6-acyl group of these adducts can be removed by triflic acid, giving further new pyrrolo-fused O- and N-heterocycles, such as 6-unsubstituted pyrrolo[1,2-c]oxazol-1(3H)-one and 1H-pyrrolo[1,2-c]imidazole-1,3(2H)-dione, while the 6-acetyl substituent of 1H-pyrrolo[1,2-c]imidazole-1,3(2H)-dione, when treated with POCl3/pyridine, is transformed into the 6-ethynyl substituent.

  • Synthesis, Transformations of Pyrrole- and 1,2,4-Triazole-Containing Ensembles, and Generation of Pyrrole-Substituted Triazole NHC
    Co-Authors: Liya D. Funt, Alexander F. Khlebnikov, Olesya A. Tomashenko, Mikhail S. Novikov, Alexander Yu. Ivanov

    Unprecedented Pyrrole- and 1,2,4-triazole-containing ensembles, substituted 1-(1H-pyrrol-3-yl)-4H-1,2,4-triazol-1-ium bromides and 4-(1H-pyrrol-3-yl)-1H-1,2,4-triazol-4-ium bromides, were prepared from 2H-azirines and triazolium phenacyl bromides using a simple procedure. N-(1H-Pyrrol-3-yl)-N′-benzyltriazolium bromides undergo reductive debenzylation on Pd/C to give substituted 1-(1H-pyrrol-3-yl)-4H-1,2,4-triazoles and 4-(1H-pyrrol-3-yl)-1H-1,2,4-triazoles in high yields. Betaines (triazoliumylpyrrolides) and pyrrolyltriazole NHCs, which are possible products of dehydrobromination of pyrrolyltriazolium salts, have comparable thermodynamic stabilities in nonpolar solvents according to calculations at the DFT B3LYP/6-31G­(d) level. The carbene forms can be easily trapped by the reaction of salts with base in the presence of sulfur. The corresponding 1- and 4-(1H-pyrrol-3-yl)-1H-1,2,4-triazole-5­(4H)-thiones are formed in high yields. In the absence of sulfur as a trap, the opening of the triazole ring occurs with the formation of derivatives of N-cyanoformimidamide. According to the DFT calculations the latter is most probably formed via a pyrrolyltriazoliumide intermediate, which is the minor component of the equilibrium triazoliumylpyrrolide–pyrrolyltriazole NHC–pyrrolyltriazoliumide. Blocking of the pyrrolyltriazoliumide intermediate formation, by introduction of a substituent at the 3-position of the triazole ring, made it possible to generate the first Pyrrole-substituted triazole NHC