131-11-3Relevant articles and documents
Microwave-promoted Beller's synthesis of substituted phthalates
Yang, Yun-Yun,Shou, Wang-Ge,Wang, Yan-Guang
, p. 1383 - 1390 (2006)
A rapid and efficient synthesis of substituted phthalates via microwave-promoted Beller's reaction of aldehydes, amides, and dimethyl acetylenedicarboxylate is described. This one-pot, multicomponent reaction was performed under acetic anhydride-free and solvent-free conditions. Copyright Taylor & Francis Group, LLC.
Comparison of three methods for the methylation of aliphatic and aromatic compounds
Lee, Hyejung,Feakins, Sarah J.,Lu, Zhiyao,Schimmelmann, Arndt,Sessions, Alex L.,Tierney, Jessica E.,Williams, Travis J.
, p. 1633 - 1640 (2017)
Rationale: Methylation protocols commonly call for acidic, hot conditions that are known to promote organic 1H/2H exchange in aromatic and aliphatic C–H bonds. Here we tested two such commonly used methods and compared a third that avoids these acidic conditions, to quantify isotope effects with each method and to directly determine acidic-exchange rates relevant to experimental conditions. Methods: We compared acidic and non-acidic methylation approaches catalyzed by hydrochloric acid, acetyl chloride and EDCI (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide)/DMAP (4-dimethylaminopyridine), respectively. These were applied to two analytes: phthalic acid (an aromatic) and octacosanoic acid (an aliphatic). We analyzed yield by gas chromatography/flame ionization (GC/FID) and hydrogen and carbon isotopic compositions by isotope ratio mass spectrometry (GC/IRMS). We quantified the 1H/2H exchange rate on dimethyl phthalate under acidic conditions with proton nuclear magnetic resonance (1H-NMR) measurements. Results: The δ2H and δ13C values and yield were equivalent among the three methods for methyl octacosanoate. The two acidic methods resulted in comparable yield and isotopic composition of dimethyl phthalate; however, the non-acidic method resulted in lower δ2H and δ13C values perhaps due to low yields. Concerns over acid-catalyzed 1H/2H exchange are unwarranted as the effect was trivial over a 12-h reaction time. Conclusions: We find product isolation yield and evaporation to be the main concerns in the accurate determination of isotopic composition. 1H/2H exchange reactions are too slow to cause measurable isotope fractionation over the typical duration and reaction conditions used in methylation. Thus, we are able to recommend continued use of acidic catalysts in such methylation reactions for both aliphatic and aromatic compounds.
Hogeeven,H.,Nusse,B.J.
, p. 3110 (1978)
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Tyerman et al.
, p. 497 (1967)
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Determination of Total Phthalate in Urine by Gas Chromatography
Albro, Phillip W.,Jordan, Sandra,Corbett, Jean T.,Schroeder, Joanna L.
, p. 247 - 250 (1984)
While urine rarely contains significant quantities of phthalate diesters, it does contain a variety of metabolites (phthalate monoesters) including conjugates.In the absence of bacterial action following excretion, the metabolites retain an intact phthalate ring.A procedure for the hydrolysis of phthalate esters and metabolites to free phthalic acid, recovery and esterification of the acid, and gas chromatographic quantification of the product ester all relative to an internal standard of 4-chlorophthalate has been developed.The measurement limit is 0.5 nmol of total phthalate/mL of urine, and the relative standard deviation is approximately 1.8percent for four or more replicates.The assay is linear between 0.5 and 50 nmol/mL urine, which spans the range of phthalate levels found thus far in human urine samples.The procedure can also be used to determine levels of isophthalate and terephthalate simultaneously with phthalate.
Preparation and isolation of isobenzofuran
Peters, Morten K.,Herges, Rainer
, p. 2659 - 2662 (2017)
The synthesis, isolation and characterization of isobenzofuran are described in this publication. Isobenzofuran is of general interest in synthetic and physical organic chemistry because it is one of the most reactive dienes known. A number of synthetic pathways have been published which all suffer from disadvantages such as low yields and difficult purification. We present a synthetic pathway to prepare isobenzofuran in laboratory scale with high yields, from affordable, commercially available starting materials.
Gribble,G.W. et al.
, p. 3673 - 3676 (1976)
Carbon-Carbon Double Bond Formation Accompanying Hydride Transfer from a Carbanion to 5-Carbalumiflavin
Farng, Oscar L.,Bruice, Thomas C.
, p. 185 - 186 (1984)
Oxidation of the carbanions of dimethyl trans-(1,2-2H0)dihydrophthalate and the corresponding (1,2-2H2) analogue occurs by H- and D- transfer to the 5-position of 5-carbalumiflavin.
Arene synthesis by extrusion reaction X. Synthesis of arenes by deoxygenation of endoxides with cyclopentadienyltitanium trichloride/lithium aluminum hydride and dicyclopentadienyltitanium dichloride/lithium aluminum hydride
Wong, Chi Hung,Hung, Chi Wai,Wong, Henry N. C.
, p. 9 - 14 (1988)
The two homogeneous systems, cyclopentadienyltitanium trichloride/lithium aluminum hydride and dicyclopentadienyltitanium dichloride/lithium aluminum hydride have been utilized to deoxygenate 1,4-endoxides in tetrahydrofuran.The results show that they can provide corresponding arenes in fair yields.
A cyclobutadiene equivalent in the catalytic Pauson-Khand reaction
Gibson, Susan E.,Mainolfi, Nello,Kalindjian, S. Barret,Wright, Paul T.
, p. 5680 - 5682 (2004)
A practical and scalable operation: The reaction shown in the scheme, which uses catalytic amounts of hexacarbonyldicobalt, gives access to versatile bicyclic systems, which until now could only be obtained in low quantities by a photochemical process starting from tropolones. An isolation of the primary Pauson-Khand products is not necessary.
Ortho-disubstitution reactions of aromatic rings with homo-conjugated bicyclo[2.2.2]octa-2,5-diene derivatives in the presence of palladium(II) acetate
Saito, Katsuhiro,Ono, Katsuhiko,Takeda, Toshifumi,Kiso, Shingo,Uenishi, Kazuya,Kozaki, Masatoshi
, p. 9081 - 9088 (2002)
Bicyclo[2.2.2]octa-2,5-diene derivatives 5 and 7 reacted with aromatic compounds such as benzene, naphthalene, anthracene, phenanthrene, and tropone in the presence of Pd(OAc)2 to afford ortho-disubstituted aromatics 6 and 8-12. Since the yields and regioselectivity were generally low, the reaction conditions were optimized by using iodoarenes as reagents to provide sufficient yields and regioselectivity. In order to investigate reactivities of diene moieties, several kinds of homo-conjugated dienes were surveyed for the reaction. Only dienes containing a bicyclo[2.2.2]octa-2,5-diene skeleton gave the ortho-disubstituted aromatics.
Kuhn,Gollnick
, p. 1909 (1972)
Identification of the Tricarbonyliron Complex of 7-Azabicycloheptadiene Derivatives as the Intermediate in Nitrene Extrusion Reactions
Sun, Chia-Hsing,Chow, Tahsin J.
, p. 535 - 536 (1988)
Several tricarbonyliron complexes of N-substituted 7-aza-2,3-bismethoxycarbonylbicycloheptadiene have been isolated and identified as the intermediates of nitrene-extrusion reactions.
Fischer,Lin
, p. 3073 (1973)
Thermally-induced Reorganization of -Ladderanes
Mehta, Goverdhan,Viswanath, M. Balaji,Kunwar, Ajit C.,Kumar, K. Ravi,Reddy, D. Siva Kumar
, p. 739 - 740 (1994)
Thermolysis of -, - and -ladderane derivatives has unravelled some novel, deep-seated rearrangements of these fascinating molecular arrays.
Synthesis and flash vacuum pyrolysis of dimethyl anti-7-nitro-2,5-norbornadiene-2,3-dicarboxylate
Marchand,Reddy,Dave
, p. 565 - 566 (1991)
Reaction of dimethyl anti-7-(trimethylsilyl)-2,5-norbornadiene-2,3-dicarboxylate (dimethyl anti-7-(trimethylsilyl)bicyclo[2.2.1]hepta-2,5-diene- 2,3-dicarboxylate, 1) with nitronium tetrafluoroborate affords the title compound 2 (65%). Subsequent photolysis of 2 affords the corresponding substituted quadricyclane derivative 3 (75%). Flash vacuum pyrolysis of 2 at 600°C affords dimethyl phthalate (67%) as the only isolable product.
Nickel-Catalyzed Carboxylation of Aryl C?F Bonds with CO2
Pei, Chunzhe,Wang, Baiquan
, p. 1245 - 1250 (2022/03/18)
The C?F bond is the strongest single bond and it is one of the most challenging tasks to achieve the C?F bond functionalization. Here, we describe the first nickel-catalyzed selective defluorinative carboxylation of aryl C?F bonds with CO2. Var
Method for coproducing methyl benzoic acid Process for the production of methyl benzoates and diesters of phthalic acids
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Paragraph 0176-0192, (2021/02/09)
The invention discloses a coproduction method of methylbenzoic acid, methyl benzoate and benzenedicarboxylic acid diester. The method comprises the following steps: (1) continuously introducing xylene, a catalyst and oxygen-containing gas into an oxidation reactor for a reaction, and controlling oxygenic concentration in the tail gas to not exceed 5% by controlling introduction amount of the oxygen-containing gas to obtain an oxidation reaction liquid; (2) feeding the obtained oxidation reaction liquid into a predistillation tower for distillation separation to obtain a low-boiling-point component and a predistillation tower bottom liquid; (3) feeding the predistillation tower bottom liquid into a distillation tower for distillation to obtain a methylbenzoic acid product and a distillationtower bottom liquid; (4) mixing the distillation tower bottom liquid and alcohol for an esterification reaction, and controlling the reaction endpoint to be lower than 0.5wt% of the content of methylbenzoic acid to obtain an esterification reaction liquid; (5) performing distillation separation on the obtained esterification reaction liquid to obtain methyl benzoate and benzenedicarboxylic acid diester products. The method has the advantages that the process is simple, equipment investment is low, and the method is environmentally friendly and has good comprehensive economic benefits.
Ultralow-Molecular-Weight Stimuli-Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides
Wu, Dehua,Song, Jintong,Qu, Lang,Zhou, Weilan,Wang, Lei,Zhou, Xiangge,Xiang, Haifeng
supporting information, p. 3370 - 3378 (2020/10/02)
The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140–200) hydrazide-derived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can self-assemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π–π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1′-binaphthalene-2,2′-diamine and S2? through much different times of gel re-formation and blue-green color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.