На основі різноманітних за будовою кумаринів шляхом розкриття лактонового фрагмента та О-алкілювання фенольного фрагмента отримано ряд нових похідних о-алкоксикоричних кислот. Дане перетворення для 3-азолілзаміщених кумаринів та фуро[3,2-g]кумаринів було здійснено у водному лужному середовищі, а для 7-гідрокси-4-метил-6-(ізокумарин-3-іл)кумарину - при нагріванні в ДМСО в присутності поташу
На основе кумаринов разнообразного строения путем раскрытия лактонного фрагмента и О-алкилирования фенольного фрагмента получен ряд новых производных о-алкоксикоричных кислот. Данное превращение в случае 3-азолилзамещенных кумаринов и фуро[3,2-g]кумаринов было проведено в водной щелочной среде, а в случае 7-гидрокси-4-метил-6-(изокумарин-3-ил)кумарина - при нагревании в ДМСО в присутствии поташа.
A number of new derivatives of o-alkoxy cinnamic acids were obtained from various coumarins by opening the lactone fragment and O-alkylation of the endocyclic Oxygen atom. The ?-hetaryl-?-(2-alkoxy-5 chlorophenyl)cinnamic acids were obtained from 3-(benzothiazol-2-yl)-6-chlorocoumarin and 3-(benzimidazol-2-yl)-6- chlorocoumarin by treatment with diluted alkali followed by p-methylbenzyl chloride or dimethyl sulfate addition, respectively. A similar reaction stages (o&pening in aqueous alkali and alkylation of the phenolate anion) was applied to the synthetic analogues of psoralen - 5-methylfuro[3,2-g]coumarins with various substituents in the furan fragment. Thus it was possible to obtain a number of 3- and 4-sub&stituted 3-(6- alkoxybenzofuran-5-yl)but-2-enoic acids. But in this case, the conversion of the starting furo[3,2-g]coumarins to cinnamic acid derivatives was not complete even after long time of reaction with a big excess of an alkylation agent. The&refore, the necessary step is the separation of the target acid from unreacted coumarin by dissolving the product in a saturated NaHCO3 solution. The insoluble part is a practically pure starting material, which can be recycled in the reaction; so th&e total yield of the product would be increased. To demonstrate the synthetic abilities of 3-(6-alkoxybenzofuran- 5-yl)but-2-enoic acids these compounds were used in synthesis of amides with pharmacophore fragments: a phenethylamine derivative with a&n additional sulfamide group and a ?-alanine derivative. The experiments showed that the 3-azolylcoumarins and furo[3,2-g]coumarins coumarin cycle"s opening occurs only in aqueous alkali, and when alkylated in an organic solvent in the presence of K2&CO3, the lactone fragment remains unchanged. The 7-hydroxy-6-(isocoumarin-3-yl)-4- methylcoumarin cycle turned out to be more labile. The result of alkylation of this compound with ethyl acetate of chloroacetic acid in the presence of K2CO3 depended &on the nature of the aprotic solvent and the temperature of reaction. So, when this reaction was carried out in boiling acetone, only the free hydroxyl group at position 7 of coumarin was alkylated. But when the initial coumarin was heated at 100 °С &with an excess of an alkylating agent in DMSO, simultaneous alkylation of both the free 7-OH group and the endocyclic Oxygen atom occurred.
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