120-61-6Relevant articles and documents
One-pot formal synthesis of biorenewable terephthalic acid from methyl coumalate and methyl pyruvate
Lee, Jennifer J.,Kraus, George A.
, p. 2111 - 2116 (2014)
Diverse functionalized aromatic compounds are constructed from captodative dienophiles with exclusive regioselectivity. 100% biorenewable dimethyl terephthalate (DMT) from methyl coumalate and methyl pyruvate is achieved in a one-pot, Diels-Alder/decarboxylation/elimination sequence in nearly quantitative yield. The DMT system is solvent-free and purification is accomplished through recrystallization. DMT hydrolysis reveals the co-monomer terephthalic acid (TPA) as a bio-based drop-in replacement for the polymer industry, avoiding harsh oxidation and petrochemicals. the Partner Organisations 2014.
Solvent dependent colorimetric, ratiometric dual sensor for copper and fluoride ions: Real sample analysis, cytotoxicity and computational studies
Senthil Murugan, Arumugam,Abel Noelson, Enose Rajan,Annaraj, Jamespandi
, p. 131 - 139 (2016)
A novel colorimetric chemosensor based on terephthalic acid and pyridine aldehyde moiety was designed to detect Cu2+/F- ions in aqueous and DMSO solutions at physiological pH conditions with the detection limit of 0.25 μM and 3 μM for Cu2+/F- ions respectively. The probe was found to be highly selective to sense F- ion rather than CH3COO- and H2PO4- ions. Interestingly, the probe behaved as a promising receptor by detecting F- ions even in ordinary tap water through distinct colour change. Moreover, the chemosensor showed lower cytotoxicity against AGS cancer cells and thus found to be biologically friendly. The reversibility of probe-F- binding was investigated using HCl in UV-vis experiment. The binding mechanism of chemosensor to Cu2+/F- ions was elucidated based on the UV-vis spectroscopy, NMR, ESI-Mass spectroscopy and cyclic voltammogram techniques. Furthermore, theoretical investigation was carried out using Gaussian 09 program.
Bioderived Muconates by Cross-Metathesis and Their Conversion into Terephthalates
Sara?i, Erisa,Wang, Lan,Theopold, Klaus H.,Lobo, Raul F.
, p. 773 - 780 (2018)
Polyethylene terephthalate that is 100 % bioderived is in high demand in the market guided by the ever-more exigent sustainability regulations with the challenge of producing renewable terephthalic acid remaining. Renewable terephthalic acid or its precursors can be obtained by Diels–Alder cycloaddition and further dehydrogenation of biomass-derived muconic acid. The cis,cis isomer of the dicarboxylic acid is typically synthesized by fermentation with genetically modified microorganisms, a process that requires complex separations to obtain a high yield of the pure product. Furthermore, the cis isomer has to be transformed into the trans,trans form and has to be esterified before it is suitable for terephthalate synthesis. To overcome these challenges, we investigated the synthesis of dialkyl muconates by cross-metathesis. The Ru-catalyzed cross-coupling of sorbates with acrylates, which can be bioderived, proceeded selectively to yield diester muconates in up to 41 % yield by using very low catalyst amounts (0.5–3.0 mol %) and no solvent. In the optimized procedure, the muconate precipitated as a solid and was easily recovered from the reaction medium. Analysis by GC–MS and NMR spectroscopy showed that this method delivered exclusively the trans,trans isomer of dimethyl muconate. The Diels–Alder reaction of dimethyl muconate with ethylene was studied in various solvents to obtain 1,4-bis(carbomethoxy)cyclohexene. The cycloaddition proceeded with very high conversions (77–100 %) and yields (70–98 %) in all of the solvents investigated, and methanol and tetrahydrofuran were the best choices. Next, the aromatization of 1,4-bis(carbomethoxy)cyclohexene to dimethyl terephthalate over a Pd/C catalyst resulted in up to 70 % yield in tetrahydrofuran under an air atmosphere. Owing to the high yield of the reaction of dimethyl muconate to 1,4-bis(carbomethoxy)cyclohexene, no separation step was needed before the aromatization. This is the first time that cross-metathesis is used to produce bioderived trans,trans-muconates as precursors to renewable terephthalates, important building blocks in the polymer industry.
Solid-phase supported nitrosocarbonyl intermediates: Old scope and new limitations in the organic synthesis
Joshi, Bhupendra Prasad,Memeo, Misal Giuseppe,Quadrelli, Paolo
, p. 3271 - 3275 (2017)
Nitrosocarbonyl intermediates on solid polystyrenic support are generated at room temperature by the mild oxidation of resin-bound stable nitrile oxides. They undergo one-pot ene reactions with tetramethyl- and trimethyl-ethylene and other highly substitu
Design, synthesis and evaluation of cholinesterase hybrid inhibitors using a natural steroidal alkaloid as precursor
Borioni, José L.,Cavallaro, Valeria,Murray, Ana P.,Pe?é?ory, Alicia B.,Puiatti, Marcelo,García, Manuela E.
, (2021)
To date, Alzheimer's disease is the most alarming neurodegenerative disorder worldwide. This illness is multifactorial in nature and cholinesterase inhibitors have been the ones used in clinical treatments. In this context, many of these drugs selectively inhibit the acetylcholinesterase enzyme interacting in both the active site and the peripheric anionic site. Besides, some agents have exhibited extensive benefits being able to co-inhibit butyrylcholinesterase. In this contribution, a strategy previously explored by numerous authors is reported; the synthesis of hybrid cholinesterase inhibitors. This strategy uses a molecule of recognized high inhibitory activity (tacrine) together with a steroidal alkaloid of natural origin using different connectors. The biological assays demonstrated the improvement in the inhibitory activity compared to the alkaloidal precursor, together with the reinforcement of the interactions in multiple sites of the enzymatic cavity. This strategy should be explored and exploited in this area. Docking and molecular dynamic studies were performed to explain enzyme-ligand interactions, assisting a structure–activity relationship analysis.
Catalysis by framework zinc in silica-based molecular sieves
Orazov, Marat,Davis, Mark E.
, p. 2264 - 2274 (2016)
Microporous and mesoporous zincosilicates (e.g., CIT-6, VPI-8, Zn-MFI, and Zn-MCM-41) synthesized in the presence of alkali cations contain two broad types of Zn sites: one that is a dication analog of the monocation ion-exchangeable Al-site in aluminosilicates, while the other resembles isolated Zn sites on amorphous silica. The ratio of these sites varies, depending on the synthesis conditions of the zincosilicate. Post-synthetic strategies based on ion-exchange can alter the site distribution towards either population. Furthermore, post-synthetic introduction of isolated Zn sites of the latter type is possible for materials possessing silanol nests. Both types of sites behave as Lewis acid centers in probe-molecule IR spectroscopy, but have very different catalytic properties. Due to the unusually high adsorption energies of Lewis bases on such materials, Lewis acid catalysis is difficult at low temperatures and in solvents bearing Lewis basic functionality. However, at high temperatures, in hydrocarbon solvents, CIT-6 (Zn-beta) is able to selectively catalyze the Lewis-acid-catalyzed Diels-Alder cycloaddition-dehydration reactions of ethylene with methyl 5-(methoxymethyl)furan-2-carboxylate, a furan that can be derived quantitatively by partial oxidation of biomass-based 5-hydroxymethylfurfural. Additionally, zinc in silica-based molecular sieves is shown here to enable chemistries previously not accessible with framework Sn-, Ti- and Zr-based Lewis acid sites, e.g., the direct production of dimethyl terephthalate by Diels-Alder cycloaddition-dehydration reactions of ethylene and the dimethyl ester of furan-2,5-dicarboxilic acid.
Preparation of monoalkyl terephthalates: An overview
Chenot, Elodie-Denise,Bernardi, Dan,Comel, Alain,Kirsch, Gilbert
, p. 483 - 490 (2007)
Terephthalic acid can be readily converted to the corresponding monoalkyl terephthalate in high yield, via a two-step procedure. This method is advantageously compared to the more representative methods described in the literature. The purification of the expected monoester, a crucial problem for this synthetic pathway, is discussed, and an original procedure has been developed. Copyright Taylor & Francis Group, LLC.
Synthesis of N, N′-bis(2-thiazolinyl)-, N, N′-bis(2-thiazolyl)- , and N, N′-bis (2-pyrimidinyl)-benzene dicarboxamides
Gondi, Sudershan R.,Son, David Y.
, p. 3061 - 3072 (2004)
New heteroaromatic benzene dicarboxamides have been synthesized in moderate to good yields by the reactions of 2-aminothiazoline, 2-aminothiazole, and 2-aminopyrimidine with phthaloyl dichloride, isophthaloyl dichloride, and terephthaloyl dichloride in the presence of an organic base. The amides are sparingly soluble in common organic solvents but dissolve readily in dimethyl sulfoxide. Reactions of 2-aminothiazoline and 2-aminopyrimidine with phthaloyl dichloride yield a tricyclic compound and an imide, respectively, instead of the expected products.
TRANSFER TECHNOLOGY I. An Improved Protocol for Chemical Synthesis.
Warrener, Ronald N.,Russell, Richard A.,Solomon, Robert,Pitt, Ian G.,Butler, Douglas N.
, p. 6503 - 6506 (1987)
A new protocol (Transfer Technology) is described in which stable molecules (Transfer Reagents) are employed as synthetic equivalents for synthons or highly reactive / unstable molecules in the preparation of substituted benzenes and other target molecules.
Highly Selective Monomethyl Esterification of Terephthalic Acid by Use of Monocarboxylate Chemisorption of Alumina
Chihara, Teiji
, p. 1215 - 1216 (1980)
When terephthalic acid, which had been chemisorbed on an alumina surface, was esterified in a stream of diazomethane, monomethyl terephthalate was obtained quantitatively.
