We have investigated the luminescent spectral properties of 3- (2-R-thiazol-4-yl)coumarins (R = CH 3, CHeCN, Ar) and some isomeric 3-(4-R-thiazol-2-yl)coumarins (R = Ar) with substituents of different electronic types both in the coumarin and in the aryl moieties. We have obtained estimates of the rate constants for primary photophysical processes: emission of fluorescence and nonradiative degrtdation of the electronic excitation energy. We have calculated the matrix elements for the spin-orbit coupling operator, and based on these matrix elements we have calculated the intersystem crossing rate constants. We have shown that deterioration of the fluorescent properties of the studied thiazolyl derivatives of coumarin when 1r-conjugated moieties are introduced into the thiazole ring is determined by the enhancement of the spin-orbit interaction in a system of levels of the 7r, 7r-type.*For communication 1, see [1].
Ensembles of rings containing coumarin units have stimulated considerable interest among researchers. These compounds include active media for lasers with effective intramolecular energy transfer [1][2][3] and promising drugs [4][5][6][7][8]. In this paper, we present results of an investigation of synthesis routes for 3-(2-R-thiazol-4-yl) and 3-(4-R-thiazol-2-yl)coumarins. Ia-f IIa-,fa-e, IXa-o I, 11 a R 1 = H; b R t = 6-OMe; c R 1 = 7-OH; d R l = 7-NEt2; e R 1 = 5,6-benzo; fR l = 6-n-C6H13 , 7-OH; rll a R 2 = H; b R 2 = CH2CN; c R 2 = Me; d R 2 = Ph; e R 2 = p-MeOC6H4; f R 2 = p-Me2NC6H4; g R 2 = p-CIC6H4; h R 2 = p-PhC6H 4, i R 2 = p-(p-PhC6H4) C6H4; IV R 2 = H; VII R 2 = p-PhC6H4; VIII R 2 = p-(p-PhC6H4) C6H4; IV, VII, VIII a R 1 = H; b R 1 = 7-OH; c R 1 = 7-NEt2; d R 1 = 5,6-benzo;. e R t = 6-n-C6H13, 7-OH; V R 2 = CH2CN; V a R 1 = H; b R 1 = 7-OH; c R I = 5,6-benzo; d R 1 = 6-n-C6HI3, 7-OH; VI R 2 = Me; VIa R l = H; b R 1 = 6-OMe; c R l = 7-OH; d R l = 7-NE~; e R 1 = 5,6-benzo; fR 1 = 6-n-C6H13, 7-OH; IXa-f R 2 = Ph; a R l = H; b R l = 6-OMe; c R t = 7-OH; d R l = 7-NEt2; e R l = 5,6-benzo; f R l = 6-n-C6H13, 7-OH; g-kR 2 = p-MeOC6H4; g R 1 = H; h R l = 7-OH; i R l = 7-NE~; j R 1 = 5,6-benzo; k R 1 = 6-n-C6H13, 7-OH; l, mR 2 = p-Me2NC6H4; l R l = 7-NEt2;mR l = 5,6-benzo; n, o R 2 = p-C1C6H4; n R 1 = H; o R 1 = H; o R l = 5,6-benzo.Ukrainian Pharmaceutical Academy, Kharkov 310002.
Recyclization of 2-Imino-2H-1-benzopyrans under the Action of Nucleophilic Reagents. Part 5. Interaction of 2-Iminocoumarin-3-carboxamide with Anthranilic Acid and Its Derivatives. -N-Substituted 2-iminocoumarins (III), (VII), (X) are formed on reacting 2iminocoumarin-3-carboxamide (I) with anthranilic acid derivatives. Depending on the reaction conditions and the nature of these imines obtained, they recyclize into the corresponding 3-substituted coumarins [→(V), (VIII)] or hydrolyze to coumarin-3-carboxamides [→(XI)]. -(KOVALENKO, S. N.; BYLOV, I. E.; BELOKON, YA. V.; CHERNYKH, V. P.; Chem. Heterocycl.
Within the synthon approach the analysis of synthetical potential of the dipolar [C2] 2/2+ - synthons is performed. The possible reaction pathways of cyclization of the dipolar electrophilic [C2]22+-synthons with the dipolar nucleophilic [SN]32-, [SN]42-, [CN]32-, [N2]32--synthons are determined. As synthetical equivalents of [C2]22+-synthons, 3-(-bromoacetyl) coumarins are chosen. On the basis of the new and improved methods of syntheseis two- and threelink biologically active assemlies of cycles with terminal coumarin links containing thriazole, indolizine, azoindolizine, 1, 3, 4-thiadiazine, furane, quinoxaline and oxazole rings are synthesized. The biological activity of 3-thiazolylcoumarins is investigated. It is stated that all of the compounds under investigation are low toxic and some of them manifest the pronounetd diuretic, antiinflammatory and membrane-stabilizing activities.
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