T 44 The first synthesis of 4-unsubstituted 3-(trifluoroacetyl)coumarins by the Knoevenagel condensation of salicylaldehydes with ethyl trifluoroacetoacetate followed by chromene-coumarin recyclization [Text] / D. L. Chizhov, V. Ya. Sosnovskikh, M. V. Pryadeina, Ya. V. Burgart, V. I. Saloutin, V. N. Charushin // Synlett. - 2008. - № 2. - P281-285 Рубрики: ХИМИЧЕСКИЕ НАУКИ \\\\expert2\\nbo\\Synlett\\2008. N 2. P. 281-285.pdf |
R 30 Reactions of 4-hydroxy-5,6,7,8-tetrafluorocoumarin derivatives with S-nucleophiles [Text] / I. T. Bazyl, S. P. Kisil', Ya. V. Burgart, V. I. Saloutin // Journal of Fluorine Chemistry. - 2000. - Vol. 103, № 1. - P3-12 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: In the reactions with o-aminothiophenol, 4-hydroxy-(3-(imino)acetyl)-5,6,7,8-tetrafluorocoumarins give products of S-substitution at the C-7 atom. 7-Substituted 5,6,8-trifluorocoumarins form benzothiazole as a result of heterocyclic ring opening; 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone undergoes acid splitting to 2-(2-hydroxy-3,4,5,6-tetrafluorophenyl)benzothiazole. Under alkaline conditions, S-substituted coumarins decompose to acetophenone. In an acid medium, 4-hydroxy-3-iminoacetyl-5,6,8-trifluoro-7-(2-aminophenylthio)coumarin affords 7-(2-aminophenylthio)-2-methyl-5,6,8-trifluorochromone. 4-Hydroxy-5,6-difluoro-2-H-pyrano[6,5-a]phenothiazin-2-one was isolated from condensation of 7-(2-aminophenylthio)-4-hydroxy-5,6,8-trifluorocoumarin in the presence of NaH.????Reactions of 3-acetyl(iminoacetyl)-4-hydroxy-5,6,7,8-tetrafluorocoumarins and 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone with 2-mercaptoethanol result in the formation of 5,7,8-trisubstituted derivatives. Interaction of 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone with 2-mercaptoethanol, mercaptoacetic acid and 1,2-ethanedithiol leads to the formation of the 7-substituted products. Acyl-lactone rearrangement of mono- and trisubstituted chromones gives the corresponding coumarins.???? |
S 53 Shcherbakov, K. V. Reactions of 5,6,7,8-tetrafluoro-4-hydroxycoumarin derivatives with benzylamine and aniline [Electronic resource] / K. V. Shcherbakov, Ya. V. Burgart, V. I. Saloutin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2006. - Vol. 55, № 7. - P1215-1219 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: 5,6,7,8-Tetrafluoro-4-hydroxycoumarin reacted with benzylamine under mild conditions to give a stable salt, while its refluxing with aniline or benzylamine in xylene afforded 5,6,7,8-tetrafluoro-4-phenyl(benzyl)aminocoumarins. Reactions of 3-acetyl(acetimidoyl)-5,6,7,8-tetrafluoro-4-hydroxycoumarins with benzylamine followed different pathways, depending on the solvent. Condensation at the acyl substituent can be accompanied by replacement of the F atom in position 7. 3-Acetylcoumarin formed a salt, while 3-acetimidoylcoumarin yielded a 7-monosubstituted product. 3-Acetyl(acetimidoyl)-5,6,7,8-tetrafluoro-4-hydroxycoumarins reacted with aniline to give only 5,6,7,8-tetrafluoro-4-hydroxy-3-(N-phenylacetimidoyl)coumarin \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2006, 55 (7), 1215-1219.pdf |
R 30 Reactions of ethyl 5,6,7,8-tetrafluoro-2-methylchromone-3-carboxylate and 3-acetimidoyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin with S-nucleophiles [Electronic resource] / I. T. Bazyl, S. P. Kisil', S. N. Frolov, Ya. V. Burgart, V. I. Saloutin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 1999. - Vol. 48, № 8. - P1537-1541 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The reactions of ethyl 5,6,7,8-tetrafluoro-2-methylchromone-3-carboxylate with mercaptoacetic acid and 1,2-ethanedithiol afforded C(7)-substitution products. The above-mentioned chromone reacted with 2-mercaptoethanol to yield 7-mono- or 5,7,8-trisubstituted products depending on the reaction conditions. The reaction of 3-acetimidoyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin with 2-mercaptoethanol afforded a 5,7,8-trisubstituted produect. The acyl-lactone rearrangement of mono- and trisubstituted chromones yielded the corresponding coumarins \\\\Expert2\\nbo\\Russian Chemical Bulletin\\1999, 48 (8), 1537.pdf |
S 73 Sosnovskikh, V. Ya. Rearrangement of 3-aminoisoxazolo[4,5-c]coumarins into 2-aminooxazolo[4,5-c]coumarins mediated by carboxylic acid anhydrides [Electronic resource] / V. Ya. Sosnovskikh, V. S. Moshkin, M. I. Kodess // Mendeleev Communications. - 2010. - Vol. 20, № 4. - P209-211 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Reactions of 3-amino-4H-chromeno[3,4-d]isoxazol-4-ones with acetic and trifluoroacetic anhydrides gave the corresponding acetyl derivatives, which were rearranged into 2-amino-4H-chromeno[3,4-d][1,3]oxazol-4-ones by heating in DMSO solution \\\\Expert2\\nbo\\Mendeleev Communications\\2010, v.20, p.209.pdf |
R 30 Reactions of 3-aminoisoxazolo[4,5-c]coumarin with benzoyl chloride: the first example of a preparative 1,2,4-oxadiazole–oxazole rearrangement [Electronic resource] / V. Ya. Sosnovskikh, V. S. Moshkin, M. Yu. Kornev, M. I. Kodess // Mendeleev Communications. - 2011. - Vol. 21, № 2. - P110-111. - Bibliogr. : p. 111 (7 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Depending on conditions, reaction of 3-amino-4H-chromeno[3,4-d]isoxazol-4-one with benzoyl chloride gives 4-hydroxy- and/or 4-benzoyloxy-3-(5-phenyl-1,2,4-oxadiazol-3-yl)coumarins, which are rearranged into 2-benzamido-4H-chromeno[3,4-d]oxazol-4-one by heating in DMSO \\\\Expert2\\nbo\\Mendeleev Communications\\2011, v.21, p.110.pdf |
1,3-Dipolar cycloadditions of nonstabilised azomethine ylides at 3-substituted coumarins: synthesis of 1-benzopyrano[3,4-c]pyrrolidines / V. S. Moshkin, V. Ya. Sosnovskikh, P. A. Slepukhin, Gerd-Volker Röschenthalerc // Mendeleev Communications. - 2012. - Vol.22, №1. - С. 29-31 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): COUMARINS -- AZOMETHINE YLIDES -- PYRROLIDINES Аннотация: Reaction of 3-substituted coumarins with N-alkyl-α-amino acids and aldehydes proceeds regio- and stereoselectively to give 1-benzopyrano[3,4-c]pyrrolidines as a result of 1,3-dipolar cycloaddition of the intermediate azomethine ylides at the Δ3-bond of the coumarins \\\\Expert2\\nbo\\Mendeleev Communications\\2012, v.22, p. 29.pdf |
A 10 A convenient approach to the design and synthesis of indolo[3,2-c]coumarins via the microwave-assisted Cadogan reaction [Electronic resource] / R. A. Irgashev, A. A. Karmatsky, P. A. Slepukhin, G. L. Rusinov, V. N. Charushin // Tetrahedron Letters. - 2013. - Vol.54, №42. - С. 5734-5738. - Bibliogr. : p. 5738 (17 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): COUMARINS -- MICROWAVE-ASSISTED -- CADOGAN REACTION Аннотация: 3-(4,5-Dimethoxy-2-nitrophenyl)coumarins bearing various substituents on the benzene ring of the coumarin system have been prepared from salicylaldehydes and 2-(4,5-dimethoxy-2-nitrophenyl)acetonitrile by means of the Perkin condensation. Further cyclization of these 3-aryl coumarins through the microwave-assisted Cadogan reaction afforded the corresponding indolo[3,2-c]coumarins in good to excellent yields \\\\expert2\\NBO\\Tetrahedron Letters\\2013, v. 54, p. 5734.pdf |
S 98 Synthesis of 4-(thien-2-yl)-substituted coumarins through Lewis acid catalyzed Michael addition of thiophenes to 3-benzoylcoumarins followed by oxidation [Electronic resource] / R. A. Irgashev, A. A. Karmatsky, G. L. Rusinov, V. N. Charushin // Tetrahedron Letters. - 2014. - Vol.55, №26. - С. 3603-3606 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): THIOPHENES -- 3-BENZOYLCOUMARINS -- Lewis acid Аннотация: 3-Benzoyl-4-(thien-2-yl)coumarins have been obtained in good yields according to the SNH addition–oxidation protocol, involving the diastereoselective addition of thiophenes at C-4 of 3-benzoylcoumarins under BBr3 catalysis, followed by oxidation of the intermediate 3,4-trans-3-benzoyl-4-(thien-2-yl)-3,4-dihydrocoumarins with DDQ. This two-step procedure can be regarded as nucleophilic substitution of hydrogen (SNH) on the heterocyclic ring of coumarins \\\\expert2\\nbo\\Tetrahedron Letters\\2014, v. 55, p. 3603.pdf |
M 61 Metal-free synthesis of 4-(thien-2-yl) substituted coumarins through direct C-H/C-H coupling of 3-benzoylcoumarins with thiophenes / A. A. Karmatsky, R. A. Irgashev, G. L. Rusinov, V. N. Charushin // Уральский научный форум "Современные проблемы органической химии". XVII Молодежная школа-конф. по органической химии, Екатернинбург, 8-12 июня 2014 г. : сб. тез. - Екатеринбург, 2014. - С. 154. - Библиогр.: с. 154 (2 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): SYNTHESIS -- THIOPHENES -- AROYLCHROMONES |
Expedient synthesis of 1,2,4-triazinyl substituted benzo[c]coumarins via double oxidation strategy / R. F. Fatykhov, I. A. Khalymbadzha, A. D. Sharapov [et al.] // Chimica Techno Acta. - 2023. - Vol. 10, № 2. - P202310205 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): COUMARIN -- 1,2,4-TRIAZINE -- NUCLEOPHILIC SUBSTITUTION OF HYDROGEN Аннотация: Herein, we report a convenient one-pot synthesis of 1,2,4-triazinyl derivatives of benzocoumarins. The proposed approach consists of the nucleophilic addition of tetrahydrobenzo annulated dimethoxycoumarin to 1,2,4-triazines followed by double oxidation of both dihydrotriazine and tetrahydrobenzo groups with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The nucleophilic addition of the dimethoxycoumarin to 1,2,4-triazines was carried out in the presence of three-fold excess of methanesulfonic acid in DCM at room temperature. It takes place between positions 8 and 5 of coumarin and 1,2,4-triazine, respectively. The double oxidation step was carried out with 3.6 equivalent of DDQ. Selective oxidation of dihydrotriazine moiety, without affecting the tetrahydrobenzo fragment, was achieved using 1.2 equivalent of tetrachlorobenzoquinone (TCQ). The differences in the oxidation with TCQ and DDQ appear to be related to the higher oxidative potential of DDQ in contrast to TCQ. The advantages of the method are the elimination of the use of transition metals, the availability of starting materials, and the simplicity of the procedure. The proposed approach provides a two-step one-pot protocol for the synthesis of triazinyl benzocoumarins, precursors for the preparation of push-pull pyridinyl chromophore. |
Conjugates of 8-[2,2’-bipyridinyl]coumarins as potential chemosensors for Al3+, Cu2+, Cd2+, Zn2+ ions: synthesis and photophysical properties / A. D. Sharapov, R. F. Fatykhov, I. A. Khalymbadzha [et al.] // Chimica Techno Acta. - 2023. - Vol. 10, № 4. - P202310417 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CHEMOSENSORS -- COUMARINS -- 2,2’-BIPYRIDINES Аннотация: In this work, we report the synthesis of novel coumarin-bipyridine conjugates using a sequence of C-C coupling reaction between 5,7-dimethoxycoumarins and 3-pyridyl-6-aryl-1,2,4-triazines followed by the Boger reaction with norbornandiene to obtain 8-[2,2'-bipyridyl]-5,7-dimethoxycoumarins. Photophysical properties were investigated for the obtained series of 8-[2,2'-bipyridyl]-5,7-dimethoxycoumarins: absorption and emission wavelength maxima are in the region of 212-296 and 401-410 nm, respectively; Stokes shifts are up to 116 nm, and fluorescence quantum yields are up to 15.0%. It was found that titrating the conjugates with Al3+, Zn2+, and Cd2+ ions results in an increase in the intensity of the emission maxima of the complexes, while the opposite effect was observed in the case of titration with Cu2+ ions. These findings suggest that the studied compounds may be considered as promising chemosensing materials. Finally, a positive solvatochromism of 8-[2,2'-bipyridyl]coumarins and their metal complexes was established. The experimental data are supported by mathematical calculations according to the Lippert-Matagaequation and Kosower diagram. |
Joy, M. N. Suzuki coupling in water: facile synthesis of novel coumarins / M. N. Joy, G. V. Zyryanov, S. Santra // Modern synthetic methodologies for creating drugs and functional materials (MOSM 2023) : book of abstracts of the 7th International conference. - Perm, 2023. - С. 72 Рубрики: ХИМИЧЕСКИЕ НАУКИ |