Розроблено новий метод синтезу системи 4Н,10Н-пірано[2,3-f]хромен-4,10-діону на основі циклізації 8-(3-диметиламіно-2-пропеноіл)-7-гідрокси-4H-хромен-4-ону в оцтовій кислоті.
Разработан новый метод синтеза системы 4Н,10Н-пирано[2,3-f]хромен-4,10-диона на основе циклізации 8-(3-диметиламино-2-пропеноил)-7-гидрокси-4H-хромен-4-она в уксусной кислоте.
A simple and efficient method for the synthesis of 4Н,10Н-pyrano[2,3-f]chromen-4,10-dione system, which is characterized by rather high yields on relatively mild conditions was offered. Design of that system has been carried out by annelation of [gama]-pirone cycle to chromone core. 4Н,10Н-Pyrano[2,3-f]chromen-4,10-dione system was elaborated using 8-(3-dimethylamino-2-propenoyl)-7-hydroxy-4H-chromen-4-one cyclization in acetic acid. The starting enaminoketone derivative was synthesized in two stages from 7-acetoxychromone. 3-(4-Chlorophenyl)-6-ethyl-2-methyl-4-oxo-4H-7-chromenyl acetate was converted into 8-acetyl-3-(4-chlorophenyl)-6-ethyl-7-hydroxy-2-methyl-4H-4-chromenone by Frice rearrangement. Subsequent heating of the latter with N,N-dimethylformamide dimethyl acetal in toluene gave the desired 3-(4-chlorophenyl)-8-(3-dimethylamino-2-propenoyl)-6-ethyl-7-hydroxy-4H-chromen-4-one. The advantage of such approach is the ability to obtain biopotent systems with different substituents in pyrone cycles, that will contribute to the search for new biologically active compounds. The structures of synthesized compounds have been assigned on the basis of analytical and spectra data.
