Facile and efficient synthesis of xanthenedione derivatives promoted by niobium pentachloride

Santos, Willian Henrique dos; Silva‐Filho, Luiz Carlos da

doi:10.1515/chempap-2016-0098

Cited by 8 publications

(5 citation statements)

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“…Lastly, the sixth absorption band had strong and sharp intensity at 1274.95 cm -1 wavenumber, signifying the C-O stretching vibration. The IR analysis results are in accordance with the study conducted by Dos Santos et al [11]. The formation of the product was also indicated by the disappearance of the signal at wave number 1714 cm -1 in the IR spectra of the product, representing the carbonyl aldehyde signal on vanillin.…”

Section: Table 1 Gc-ms Analysis Of Synthesized Compounds Without Cata...supporting

confidence: 90%

“…A number of methods have been developed to synthesize Compound 1, such as the reflux method with a stirrer and alumina-sulfuric acid catalyst [9], reflux with NbCl5 catalyst [11], and heating with VOSO4 catalyst [12]. Those three catalysts have been reported to synthesize Compound 1 efficiently, but they presented a complicated catalyst preparation.…”

Section: Introductionmentioning

confidence: 99%

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Assisted ultrasonic wave of vanillin derivatives synthesis and antioxidant activity using DPPH method

Retnosari¹,

Sari²,

Marfuah³

et al. 2022

CST

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In recent years, the need for compounds with antioxidant activities have expanded. Generally, the natures of these compounds involve the presence of conjugated double bonds, phenolic groups, and resonance effects on the structure. One of the compounds with the phenolic group is vanillin. It can be modified into the derivative of 1,8-dioxo-octahydroxantene compound due to its aldehyde content. Meanwhile, 1,8-dioxo-octahydroxantene compound has two 2- cyclohexenone rings bound in the pyran ring and one phenolic group, expected to carry more excellent antioxidant activity than vanillin. The 9-(4-hydroxy-3-methoxyphenyl)-3,4,5,6,7,9- hexahydro -1H-xantene-1,8(2H)-dione (Compound 1) was synthesized from 1,3- cyclohexanedione and vanillin through Knoevenagel's condensation reaction aided with an acid catalyst with a single reaction phase. Besides, green chemistry was adopted in this study using environmentally friendly catalysts from lime juice and ultrasonic wave. The synthesized compounds' structure was confirmed through the spectrophotometer IR, GC-MS, and 1H-NMR spectrometer, while its antioxidant activity was tested using the DPPH method. The reaction occurred with and without lime juice catalyst, producing yields of 6.65% and 70.58%, respectively. The results of the antioxidant activity test suggest that Compound 1 carries substantially robust antioxidant activities, with IC50 of 0.99 ppm.

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Section: Table 1 Gc-ms Analysis Of Synthesized Compounds Without Cata...supporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Assisted ultrasonic wave of vanillin derivatives synthesis and antioxidant activity using DPPH method

Retnosari¹,

Sari²,

Marfuah³

et al. 2022

CST

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show abstract

“…13 In a study recently published by our research group, a new method for the synthesis of xanthenedione derivatives through a reaction between dihydroresorcinol (10) and benzaldehyde derivatives in the presence of NbCl 5 was described. 14 Based on this work and on our experimental results, we propose a plausible mechanism that begins with the Knoevenagel condensation reaction between the activated aldehydes II and I, followed by the elimination of H 2 O, producing the intermediate IV (Scheme 3). The Intermediate IV acts as a Michael acceptor and is activated by NbCl 5 .…”

Section: Scheme 2 Synthesis Of Methoxylated Phloroglucinol Derivativementioning

confidence: 67%

“…Based on these results, entry 15 was established as the best reaction conditions applied for the other performed reactions. We hy- pothesize that the low solubility of some aldehydes and reactive intermediates may explain the differences in product yields when the solvent mixtures were varied (entries [13][14][15][16][17][18][19][20]. We investigated the profile of this reaction by using other aldehydes 11b-m containing electron-donating and electron-withdrawing groups obtaining the phloroglucinol derivatives in analogous yields.…”

Section: Scheme 2 Synthesis Of Methoxylated Phloroglucinol Derivativementioning

confidence: 99%

One-Step Synthesis of Methoxylated Phloroglucinol Derivatives Promoted by Niobium Pentachloride: An Experimental and Theoretical Approach

et al. 2017

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S3COMPUTATIONAL DETAILS: All DFT calculations were performed with Gaussian 09 suit of programs using a ultrafine grid [2].Full optimization were conducted in vacuum employing the B3LYP functional with 6-31G(d) basis set. Frequency calculations at 295.15 K (1 atm) ensured that the stationary points represent either minima (no imaginary frequency) or transition states (single imaginary frequency) on the potential-energy surface. The pre-activated complexes were obtained from the first point of the IRC curves. To refine the electronic energy, single-point calculations were performed at the B3LYP/6-311+G(d,p) level of theory with IEF-PCM (in acetonitrile or dichloromethane) and Grimme's D3 dispersion model [3], employing the B3LYP/6-31G(d) geometries. The IRC calculations were done at B3LYP/6-31G(d) ensuring that each transition state connects reagents and products.

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“…The condensation of two molecules of 1,3-cyclohexanediones with aromatic aldehydes usually produces 9-substituted octahydroxanthene [14][15][16] and tetrahydroxanthene derivatives with 2-hydroxyaromatic aldehydes [17]. The reaction mechanism involves the condensation of Knoevenagel of the molecule of cy-clohexanedione with aldehyde and subsequent Michael addition of the second molecule to formed α, βunsaturated diketone.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 4-(2-Hydroxyphenyl)-5,6,7,8-Tetrahydroisoxazolo [5,4-B]chromene-5(4h)-Ones

Pyrko¹

2018

IVUZKKT

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The aim of this work is the synthesis of new tetraheterocyclic compounds of interest as potential biologically active substances that include the isoxazole and chromone moieties in their structure. The synthesis of such compounds was carried out with two stages. By Knoevenagel condensation of 3-methyl-1,2-isoxazol-5(2H)-on with salicylic aldehyde (4Z)-4-(2-hydro-xybenzyliden)-3-methyl-1,2-oxazol-5(4H)-on was obtained. In this reaction an excess of half of the aldehyde equivalent was used to increase the yield of the product. Pyperidine was used as a catalyst. The reaction was carried out by boiling the components in ethyl acetate. The reaction of the resulting benzylidenisoxazole derivative with cyclohexane-1,3-dione or dimedone was performed by boiling the components in ethanol without the use of a catalyst. The interaction mechanism includes heterodiene Dielsa-Aldera condensation followed by dehydration of one water molecule. As a result, 3-methyl-4-(2-hydroxyphenyl-5,6,7,8-tetrahydroisoxazolo[5,4-b]chromene-5(4H)-one and 3,7,7-trimethyl-4-(2-hydroxyphenyl)-5,6,7,8,9-tetrahydroisoxazolo[5,4-b]chromen-5(4H)–one were obtained. Purification of the synthesized compounds was carried out by crystallization from ethanol. All the obtained compounds were characterised by IR 1H NMR and UV spectroscopies. In 1H NMR spectra there are signals of the methyl groups of the isoxazole ring of compounds at 2.26, 2.29, 2.34 ppm respectively. In the UV spectrum of a plane molecule of (4Z)-4-(2-hydroxybenzyliden)-3-methyl-1,2-oxazol-5(4H)-on there is a long-wave absorption maximum (400.9 nm) corresponding to the joint system of conjugated bonds of the isoxazole and aromatic rings. The structures of the obtained compounds were confirmed by high resolution mass-spectrometry analysis. In the spectra of 3-methyl-4-(2-hydroxyphenyl-5,6,7,8-tetrahydroisoxazolo[5,4-b]chromene-5(4H)-one and 3,7,7-trimethyl-4-(2-hydroxyphenyl)-5,6,7,8,9-tetrahydroisoxazolo[5,4-b]chromen-5(4H)–one the[M + Na]+ ion peaks were observed. The presence of fragment peaks [M + Na – CO]+ and [M + Na – CO – H2O]+ confirms the presence of hydroxy and carbonyl groups in the molecules.

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Facile and efficient synthesis of xanthenedione derivatives promoted by niobium pentachloride

Cited by 8 publications

References 65 publications

Assisted ultrasonic wave of vanillin derivatives synthesis and antioxidant activity using DPPH method

Assisted ultrasonic wave of vanillin derivatives synthesis and antioxidant activity using DPPH method

One-Step Synthesis of Methoxylated Phloroglucinol Derivatives Promoted by Niobium Pentachloride: An Experimental and Theoretical Approach

Synthesis of 4-(2-Hydroxyphenyl)-5,6,7,8-Tetrahydroisoxazolo [5,4-B]chromene-5(4h)-Ones

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