Mannich bases of hydroxycoumarins: synthesis, DFT ... - RSC …
The 7-hydroxy-4-methylcoumarin derivatives (5a–5c) showed a relevant interaction between the relatively acidic hydrogen atom of the hydroxyl substituent and the lone pair of the tertiary amine, which produces a thermodynamically favoured six-membered ring structure .
Overview on developed synthesis procedures of coumarin …
2020年6月27日 · Coumarin derivatives 464 were prepared of 7-hydroxy-4-methyl coumarin 3 as a precursor, which was synthesized from resorcinol 1 and ethyl acetoacetate 2 in the presence of H 2 SO 4. Further, the formed compound 3 was acylated using acetic acid in the presence of phosphorus oxychloride.
Study on effective synthesis of 7-hydroxy-4-substituted coumarins
In this work, based on the Pechmann coumarin synthesis method, the influence of various Lewis acids on the reaction was discussed, and the optimal synthesis conditions of 7-hydroxy-4-substituted coumarins were explored.
Coumarins, Pyrenes and Other Ultraviolet Light–Excitable …
Compared with 7-hydroxy-4-methylcoumarin (pKa = 7.8), DiFMU (pKa = 4.9) provides superior detection sensitivity in the 5–8 pH range under these conditions. The hydroxycoumarins exhibit pH-sensitive spectral properties, but the methoxycoumarins do not.
Synthesis of 7-hydroxy-4-methylcoumarin via the Pechmann reaction …
2016年11月1日 · A novel method for synthesis of 7-hydroxy-4-methylcoumarin from resorcinol and ethyl acetoacetate via the Pechmann reaction with polyvinylpyrrolidone-supported phosphotungstic acid (PVP–HPW) catalyst is developed. The catalysts were characterized by FTIR, TGA, elemental analysis, UV–vis and a Hammet acidity function test.
Theoretical and Experimental Study on the 7‐Hydroxy‐4‐Methylcoumarin …
2019年9月23日 · The synthesis of the 7-hydroxy-4-methylcoumarin via the Pechmann reaction from the resorcinol and the ethyl acetoacetate on H-Beta zeolite was studied by using combination of DFT calculation and experimental methods. The adsorption was examined by the FT-IR technique.
The coumarin synthesis: a combined experimental and ... - Springer
2017年5月18日 · The synthesis of 7-hydroxy-4-methylcoumarin from resorcinol and ethyl acetoacetate with sulfuric acid as a catalyst has been studied experimentally and theoretically. The synthesized 7-hydroxy-4-methylcoumarin was confirmed by spectroscopy techniques.
Mechanical, optical and antioxidant properties of 7-Hydroxy-4 …
2020年10月24日 · In the present study, the different weight ratios of 7-hydroxy-4-methyl coumarin (7H4MC) mixed polyvinyl alcohol (PVA)/oxidized maize starch (OMS) blend films were achieved by the solvent casting method and coded as PSC.
Hymecromone | C10H8O3 | CID 5280567 - PubChem
4-methylumbelliferone is a hydroxycoumarin that is umbelliferone substituted by a methyl group at position 4. It has a role as an antineoplastic agent and a hyaluronic acid synthesis inhibitor. It is functionally related to an umbelliferone.
7-Hydroxy-4-methylcoumarin 97% | Sigma-Aldrich
A series of new coumarin-based 1,2,4-triazole derivatives were designed, synthesized and evaluated for their antimicrobial activities in vitro against four Gram-positive bacteria (Staphylococcus aureus, MRSA, Bacillus subtilis and Micrococcus luteus), four Gram-negative bacteria (Escherichia coli, Proteus vulgaris, Salmonella typhi and
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