Condensation of Formaldehyde With Phloroglucinol and Its Monomethyl Ether

Kiehlmann, Eberhard; Lathioor, Edward C.; Lai, Kwong Wah

doi:10.1080/00304949609356520

Cited by 8 publications

(6 citation statements)

References 7 publications

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“…On the other hand, precursor B is derived from the reaction of salicylaldehyde with phloroglucinol again in a 3:1 ratio and a dark yellow liquid condensation product is obtained. 37 Salicylaldehyde is taken three times with respect to phloroglucinol such that they can undergo condensation at the 2, 4, and 6 positions of the latter. The reaction times for both the precursors are kept short at 4 h such that the condensation reactions are initiated but not completed and there is scope for further condensation and cross-linking when the two precursors are mixed subsequently.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The ratio is kept at 3:1 as each melamine moiety has three -NH 2 groups and can undergo Schiff base condensation with the aldehyde groups of three salicyladehyde moieties. On the other hand, precursor B is derived from the reaction of salicylaldehyde with phloroglucinol again in a 3:1 ratio and a dark yellow liquid condensation product is obtained . Salicylaldehyde is taken three times with respect to phloroglucinol such that they can undergo condensation at the 2, 4, and 6 positions of the latter.…”

Section: Results and Discussionmentioning

confidence: 99%

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Morphology Controlled Synthesis of Heteroatom-Doped Spherical Porous Carbon Particles Retaining High Specific Capacitance at High Current Density

Pal

Ghosh

Singha

et al. 2021

ACS Appl. Energy Mater.

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A polymer precursor based on phlorogucinol-salicyaldehyde-melamine (PSM@silica) has been synthesized using pluronic P123 and tetratethyl orthosilane as the structure directing matrix. The polymer has been pyrolyzed under nitrogen flow at different temperatures from 700 to 1000 °C to obtain the corresponding carbons, CPSM-700, CPSM-800, CPSM-900, and CPSM-1000. Carbonization temperature is found to play an important role on the morphology, heteroatom content, and surface area of the products. The samples have been characterized by various techniques such as powder X-ray diffraction, nitrogen adsorption/desorption, scanning electron microscopy and X-ray photoelectron spectroscopy studies. The spherical carbon particles of micron meter diameters with high surface area and heteroatom doping (O, N) make them potential candidates for electrochemical applications. Detailed electrochemical studies have been carried out for all the samples by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) in 1 M H2SO4 electrolyte. It is found that CPSM-900 shows the best results with specific capacitance of 400 F·g–1 at 0.6 A·g–1 current density. Remarkably, at high current density of 12.16 A·g–1 it still retains a very high value of 270 F·g–1. Its well-defined spherical morphology (ca. 1.16 μm diameters), high Brunauer–Emmett–Teller (BET) surface area (712 m2·g–1), and nitrogen content of ca. 2.61% are responsible for its superior performance. It shows high specific energy density and a power density of 44.92 Wh·kg–1 and 274.116 W·kg–1, respectively, at a current density of 0.6 A·g–1. The corresponding values are maintained up to 30.37 Wh·kg–1 and 5461.5 W·kg–1 at 12.16 A·g–1. The material is highly stable with no loss of specific capacitance up to 5000 cycles at 6.21 A·g–1 current density.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Morphology Controlled Synthesis of Heteroatom-Doped Spherical Porous Carbon Particles Retaining High Specific Capacitance at High Current Density

Pal

Ghosh

Singha

et al. 2021

ACS Appl. Energy Mater.

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“…Comparison of the 1 H and 13 C NMR spectroscopic data of 5 with those of previously reported synthetic bis (2,4,6-trihydroxy-3-(2ʹ4',6ʹ-trihydroxybenzyl)phenyl)methane (4) [16] showed the signals of both compounds to closely resemble one another, but the resonances for the absence of an aromatic proton at the C-12 position in 5, and the presence of two aromatic protons at C-2, −4 and one methylene proton at C-6a, indicating that a phloroglucinol moiety was linked through the methylene bridge in 5. The linkage positions of the methylene bridge residues in 5 were unambiguously elucidated by key HMBC correlations as shown in Figure 2(a).…”

Section: Resultsmentioning

confidence: 93%

“…The dried phloroglucinol treated for 60 min showed the most improved inhibitory activity, with an IC 50 value of 15.6 ± 1.7 μg/ mL in the α-glucosidase inhibition assay. Chromatographic separation resulted in the isolation of a novel methylene-bridged pentameric phloroglucinol 5, along with three previously known oligomeric phloroglucinols, bis(2,4,6-trihydroxyphenyl)methane (2) [16], 2,4-bis (2ʹ,4ʹ,6ʹ-trihydroxybenzyl)phloroglucinol (3) [16], and bis (2,4,6-trihydroxy-3-(2ʹ4',6ʹ-trihydroxybenzyl)phenyl)methane (4) [16] (Figure 1). The isolated compounds were identified by comparison of their spectroscopic data with the literature values.…”

Section: Resultsmentioning

confidence: 99%

A green chemical oligomerization of phloroglucinol induced by plasma as novel α-glucosidase inhibitors

Choi

Jeong

Lee

et al. 2018

Bioscience, Biotechnology, and Biochemistry

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A new facile method was developed for simple green synthesis of methylene-bridged phloroglucinol oligomers using nonthermal dielectric barrier discharge (DBD) plasma in methanolic solution. The chemical structures of these newly generated oligomers 2-5 were determined by interpretation of the spectroscopic data, and the inhibitory activity toward α-glucosidase of all isolates was evaluated. The unusual phloroglcuinol pentamer 5 connected by four methylene linkages showed a much higher potential inhibitory effect against α-glucosidase than the other generated oligomers 2-4 and appeared to be a promising lead for development as a potential antidiabetic agent. Abbreviations: T2DM, type2 diabetes mellitus; DBD, dielectric barrier discharge; HPLC, high-performance liquid chromatography; IC50, 50% inhibition concentration; NMR, nuclear magnetic resonance; FABMS, fastatom bombardment mass spectrometry.

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“…According to findings by Kiatgrajai et al 22 , and Kiehlmann et al . 23 , flavan 3-ols analogue is generated as oligomers through a methylene-bridge by formaldehyde, and EGCG dimers 2 and 3 were synthesized and identified as oolonghomobisflavans A and B by Hahimoto et al . 24 and Jeong et al .…”

Section: Resultsmentioning

confidence: 99%

Mechanism of (−)-epigallocatechin gallate (EGCG) dimerization by low-temperature plasma

Park

Jeong

Jee

et al. 2022

Sci Rep

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The efficient dimerization of (−)-Epigallocatechin gallate (EGCG), which is the major bioactive constituent isolated from the leaves of Camellia sinensis, was initially reported without changes in its stereochemistry using low-temperature plasma. The contribution of plasma during the dimerization of EGCG in a methanolic solution was quantified using a major factor, with the major factor demonstrated based on the contents of newly generated products, in this case the sum of oolonghomobisflavans A and B depending on the plasma treatment method. Samples were treated in three methods: plasma direct treatment, an indirect treatment using only reactive species, and an indirect treatment using effects other than those by reactive species. Ozone was identified as a major factor during the plasma treatment, and the operating ranges of the ozone concentration for regulated dimerization were evaluated. The mechanism by which EGCG synthesizes dimers A and B during the treatment process using low-temperature plasma was investigated using the derived major factor and prior literature. The ozone generated by the plasma reacted with methanol to form formaldehyde, and dimers A and B were synthesized by oligomers through a methylene-bridge by the formaldehyde. A plausible pathway of regulated dimerization was deduced based on these results, and the mechanism of EGCG dimerization by plasma is described using this pathway.

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Condensation of Formaldehyde With Phloroglucinol and Its Monomethyl Ether

Cited by 8 publications

References 7 publications

Morphology Controlled Synthesis of Heteroatom-Doped Spherical Porous Carbon Particles Retaining High Specific Capacitance at High Current Density

Morphology Controlled Synthesis of Heteroatom-Doped Spherical Porous Carbon Particles Retaining High Specific Capacitance at High Current Density

A green chemical oligomerization of phloroglucinol induced by plasma as novel α-glucosidase inhibitors

Mechanism of (−)-epigallocatechin gallate (EGCG) dimerization by low-temperature plasma

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