Unknown

Dataset Information

0

Synthesis and Characterization of New Pyrano[2,3-c]pyrazole Derivatives as 3-Hydroxyflavone Analogues.


ABSTRACT: In this paper, an efficient synthetic route from pyrazole-chalcones to novel 6-aryl-5-hydroxy-2-phenylpyrano[2,3-c]pyrazol-4(2H)-ones as 3-hydroxyflavone analogues is described. The methylation of 5-hydroxy-2,6-phenylpyrano[2,3-c]pyrazol-4(2H)-one with methyl iodide in the presence of a base yielded a compound containing a 5-methoxy group, while the analogous reaction of 5-hydroxy-2-phenyl-6-(pyridin-4-yl)pyrano[2,3-c]pyrazol-4(2H)-one led to the zwitterionic 6-(N-methylpyridinium)pyrano[2,3-c]pyrazol derivative. The treatment of 5-hydroxy-2,6-phenylpyrano[2,3-c]pyrazol-4(2H)-one with triflic anhydride afforded a 5-trifloylsubstituted compound, which was further used in carbon-carbon bond forming Pd-catalyzed coupling reactions to yield 5-(hetero)aryl- and 5-carbo-functionalized pyrano[2,3-c]pyrazoles. The excited-state intramolecular proton transfer (ESIPT) reaction of 5-hydroxypyrano[2,3-c]pyrazoles from the 5-hydroxy moiety to the carbonyl group in polar protic, polar aprotic, and nonpolar solvents was observed, resulting in well-resolved two-band fluorescence. The structures of the novel heterocyclic compounds were confirmed by 1H-, 13C-, 15N-, and 19F-NMR spectroscopy, HRMS, and single-crystal X-ray diffraction data.

SUBMITTER: Urbonavicius A 

PROVIDER: S-EPMC10537540 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature

altmetric image

Publications

Synthesis and Characterization of New Pyrano[2,3-<i>c</i>]pyrazole Derivatives as 3-Hydroxyflavone Analogues.

Urbonavičius Arminas A   Krikštolaitytė Sonata S   Bieliauskas Aurimas A   Martynaitis Vytas V   Solovjova Joana J   Žukauskaitė Asta A   Arbačiauskienė Eglė E   Šačkus Algirdas A  

Molecules (Basel, Switzerland) 20230913 18


In this paper, an efficient synthetic route from pyrazole-chalcones to novel 6-aryl-5-hydroxy-2-phenylpyrano[2,3-<i>c</i>]pyrazol-4(2<i>H</i>)-ones as 3-hydroxyflavone analogues is described. The methylation of 5-hydroxy-2,6-phenylpyrano[2,3-<i>c</i>]pyrazol-4(2<i>H</i>)-one with methyl iodide in the presence of a base yielded a compound containing a 5-methoxy group, while the analogous reaction of 5-hydroxy-2-phenyl-6-(pyridin-4-yl)pyrano[2,3-<i>c</i>]pyrazol-4(2<i>H</i>)-one led to the zwitter  ...[more]

Similar Datasets

| S-EPMC8622706 | biostudies-literature
| S-EPMC11470616 | biostudies-literature
| S-EPMC8634879 | biostudies-literature
| S-EPMC10892497 | biostudies-literature
| S-EPMC3099764 | biostudies-literature
| S-EPMC9091629 | biostudies-literature
| S-EPMC9090729 | biostudies-literature
| S-EPMC10373183 | biostudies-literature
| S-EPMC6270532 | biostudies-literature
| S-EPMC7114146 | biostudies-literature