2306-33-4Relevant academic research and scientific papers
Ultrasonic enhancement on the hydrolysis of diethyl 1,2-benzenedicarboxylate
Yim, Bongbeen,Yoo, Youngeok,Nagata, Yoshio,Maeda, Yasuaki
, p. 938 - 939 (2001)
The ultrasonic enhancement on the hydrolysis of diethyl 1,2-benzenedicarboxylate results from the dissipated heat when the cavitation micro-bubbles were vigorously collapsed. The effective temperature in a solution depends on the nature of the dissolved gas. The relatively broad region that spreads from the interface of the cavitation micro-bubble plays an important role in the sonolytic hydrolysis of esters.
Synthesis of New Dialkyl 2,2′-[Carbonyl bis (azanediyl)]dibenzoates via Curtius Rearrangement
Yassine, Hasna,Bouali, Jamila,Oumessaoud, Asmaa,Ourhzif, El Mahdi,Hamri, Salha,Hafid, Abderrafia,Khouili, Mostafa,Pujol, Maria Dolors
, p. 1971 - 1979 (2021/01/21)
The 2-(alkylcarbonyl)benzoic acids obtained by esterification of phthalic anhydride are converted into azide derivatives: alkyl 2-[(azidocarbonyl)amino]benzoates and to ureas: dialkyl 2,2′-[carbonyl bis (azanediyl)]dibenzoates. These transformations were carried out using classical Curtius rearrangement conditions in the presence of diphenylphosphoryl azide (DPPA) in a basic medium, followed by hydrolysis. Subsequently, a final condensation reaction of these urea derivatives enabled us to obtain, for the first time, the new alkyl derivatives, alkyl 2-[2,4-dioxo-1,2-dihydroquinazolin-3(4 H)-yl]benzoates. All the new compounds obtained in satisfactory yields were characterized by 1H and 13C NMR, and by X-ray crystallographic analysis.
Palladium-Catalyzed Carboxylate-Assisted Ethoxycarboxylation of Aromatic Acids to Synthesize Monoethyl Phthalate Derivatives with Ethyl Bromodifluoroacetate
Tao, Na,Wang, Jie,Yuan, Chunchen,Zeng, Runsheng,Zhao, Ying-Sheng
supporting information, p. 8607 - 8610 (2019/11/03)
A novel and efficient approach for direct carbonation of aromatic acids with ethyl bromodifluoroacetate as the carbonyl source is reported. A broad range of substrates bearing various functional groups were tolerated, leading to monoalkyl phthalate derivatives in moderate to good yields.
Automated on-line monitoring of the TiO2-based photocatalytic degradation of dimethyl phthalate and diethyl phthalate
Salazar-Beltrán, Daniel,Hinojosa-Reyes, Laura,Maya-Alejandro, Fernando,Turnes-Palomino, Gemma,Palomino-Cabello, Carlos,Hernández-Ramírez, Aracely,Guzmán-Mar, Jorge Luis
, p. 863 - 870 (2019/04/17)
A fully automated on-line system for monitoring the TiO2-based photocatalytic degradation of dimethyl phthalate (DMP) and diethyl phthalate (DEP) using sequential injection analysis (SIA) coupled to liquid chromatography (LC) with UV detection was proposed. The effects of the type of catalyst (sol-gel, Degussa P25 and Hombikat), the amount of catalyst (0.5, 1.0 and 1.5 g L-1), and the solution pH (4, 7 and 10) were evaluated through a three-level fractional factorial design (FFD) to verify the influence of the factors on the response variable (degradation efficiency, %). As a result of FFD evaluation, the main factor that influences the process is the type of catalyst. Degradation percentages close to 100% under UV-vis radiation were reached using the two commercial TiO2 materials, which present mixed phases (anatase/rutile), Degussa P25 (82%/18%) and Hombikat (76%/24%). 60% degradation was obtained using the laboratory-made pure anatase crystalline TiO2 phase. The pH and amount of catalyst showed minimum significant effect on the degradation efficiencies of DMP and DEP. Greater degradation efficiency was achieved using Degussa P25 at pH 10 with 1.5 g L-1 catalyst dosage. Under these conditions, complete degradation and 92% mineralization were achieved after 300 min of reaction. Additionally, a drastic decrease in the concentration of BOD5 and COD was observed, which results in significant enhancement of their biodegradability obtaining a BOD5/COD index of 0.66 after the photocatalytic treatment. The main intermediate products found were dimethyl 4-hydroxyphthalate, 4-hydroxy-diethyl phthalate, phthalic acid and phthalic anhydride indicating that the photocatalytic degradation pathway involved the hydrolysis reaction of the aliphatic chain and hydroxylation of the aromatic ring, obtaining products with lower toxicity than the initial molecules.
Practical selective monohydrolysis of bulky symmetric diesters
Shi, Jianjun,Niwayama, Satomi
, p. 799 - 802 (2018/02/10)
The highly efficient selective monohydrolysis reaction we previously reported has been applied to monohydrolysis of several bulkyl symmetric diesters, including diethyl esters, dipropyl esters, and dibutyl esters. A greater proportion of a polar aprotic co-solvent, DMSO, and aqueous KOH appear to help improve the reactivity of bulky diesters compared to the corresponding dimethyl esters. The procedure is mild and practical, yielding the corresponding half-esters in high yields under simple conditions.
Practical selective monohydrolysis of bulky symmetric diesters: Comparing with sonochemistry
Shi, Jianjun,Zhao, Tian,Niwayama, Satomi
, p. 6815 - 6820 (2018/10/20)
The conditions of the practical selective monohydrolysis of symmetric diesters we previously reported have been modified and applied to selective monohydrolysis of bulky symmetric diesters. While ultrasound is generally considered effective for two-phase reactions, its effect actually turned out to be rather marginal. Instead, use of a larger proportion of a polar aprotic co-solvent, DMSO, and aqueous KOH helped enhance the reaction rates and improve the yields of the half-esters. The reactions are simple, mild and practical without special devices.
Preparation method of butylphthalide and pharmaceutical intermediate thereof
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Paragraph 0023, (2018/11/03)
The present invention provides a new pharmaceutical intermediate and a method for preparing butylphthalide by using the new pharmaceutical intermediate. According to the method, o-phthalic acid monoester as a raw material and valerate are subjected to ester condensation, o-pentanoylbenzoic acid is prepared through hydrolysis and decarboxylation, and reducing with sodium borohydride and ring closure are performed to obtain the product. According to the present invention, the method has characteristics of inexpensive and easily-available raw material, mild reaction condition, no high-temperaturereaction, no Grignard reaction, production energy consumption reducing, production cost reducing and operation safety improving.
Carboxylation of Aromatic and Aliphatic Bromides and Triflates with CO2 by Dual Visible-Light–Nickel Catalysis
Meng, Qing-Yuan,Wang, Shun,K?nig, Burkhard
supporting information, p. 13426 - 13430 (2017/10/07)
We report the efficient carboxylation of bromides and triflates with K2CO3 as the source of CO2 in the presence of an organic photocatalyst in combination with a nickel complex under visible light irradiation at room temperature. The reaction is compatible with a variety of functional groups and has been successfully applied to the synthesis and derivatization of biologically active molecules. In particular, the carboxylation of unactivated cyclic alkyl bromides proceeded well with our protocol, thus extending the scope of this transformation. Spectroscopic and spectroelectrochemical investigations indicated the generation of a Ni0 species as a catalytic reactive intermediate.
Photocatalysis in dimethyl carbonate green solvent: Degradation and partial oxidation of phenanthrene on supported TiO2
Bellardita,Loddo,Mele,Panzeri,Parrino,Pibiri,Palmisano
, p. 40859 - 40864 (2015/01/08)
Dimethyl carbonate (DMC) is here proposed-for the first time-as a green organic solvent for photocatalytic synthesis. In this work, the photocatalytic partial oxidation of phenanthrene in dimethyl carbonate (DMC) by using anatase TiO2as the photocatalyst is described as paradigmatic example of a green synthetic process starting from polycyclic aromatic hydrocarbons (PAHs). For comparison, the same reaction carried out also in ethanol, 1-propanol or 2-propanol is reported. The use of DMC as the solvent allowed us to achieve 19% and 23% selectivity towards 9-fluorenone and 6H-benzo[c]chromen-6-one, respectively. The proposed approach may represent both a new green synthetic process and an environmentally friendly route to degradation of PAHs. This journal is
Extremely fast gas/liquid reactions in flow microreactors: Carboxylation of short-lived organolithiums
Nagaki, Aiichiro,Takahashi, Yusuke,Yoshida, Jun-Ichi
, p. 7931 - 7934 (2014/07/07)
Carboxylation of short-lived organolithiums bearing electrophilic functional groups such as nitro, cyano, and alkoxycarbonyl groups with CO 2 to give carboxylic acids and active esters was accomplished in a flow microreactor system. The successful reactions indicate that gas/liquid mass transfer and the subsequent chemical reaction with CO2 are extremely fast. Carboxylation of short-lived organolithiums bearing electrophilic functional groups such as nitro, cyano, and alkoxycarbonyl groups with CO 2 to give carboxylic acids and active esters was accomplished in a flow microreactor system. The successful reactions indicate that gas/liquid mass transfer and the subsequent chemical reaction with CO2 are extremely fast (see scheme).
