- Diorganotin complexes of carboxylates: Synthesis and characterization
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Diorganotin complexes of monoisopropyl and monomethyl nadiate, succinate, and phthalate were synthesized and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, and 119Sn NMR spectroscopic techniques. The spectroscopic investigation demonstrated that carboxylate is bidentate in the diorganotin complexes. On the basis of 1J(119Sn-13C) and 2J(119Sn-1H) values, C-Sn-C bond angles were also calculated. The newly synthesized complexes were also screened for their antibacterial activities against Gram-positive and Gram-negative pathogenic strains of bacteria.
- Chilwal, Asha,Deep, Gagan,Malhotra, Priti,Narula
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Read Online
- Synthesis of New Dialkyl 2,2′-[Carbonyl bis (azanediyl)]dibenzoates via Curtius Rearrangement
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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.
- Yassine, Hasna,Bouali, Jamila,Oumessaoud, Asmaa,Ourhzif, El Mahdi,Hamri, Salha,Hafid, Abderrafia,Khouili, Mostafa,Pujol, Maria Dolors
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p. 1971 - 1979
(2021/01/21)
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- CYCLIC PHOSPHATE COMPOUNDS
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Provided herein are cyclic phosphate compounds, their preparation and their uses, such as treating liver diseases or conditions or a disease or condition in which the physiological or pathogenic pathways involve the liver.
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Paragraph 0195-0197
(2020/11/04)
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- Practical selective monohydrolysis of bulky symmetric diesters
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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.
- Shi, Jianjun,Niwayama, Satomi
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p. 799 - 802
(2018/02/10)
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- Practical selective monohydrolysis of bulky symmetric diesters: Comparing with sonochemistry
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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.
- Shi, Jianjun,Zhao, Tian,Niwayama, Satomi
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p. 6815 - 6820
(2018/10/20)
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- Cobalt-Catalyzed Carbonylation of C(sp2)-H Bonds with Azodicarboxylate as the Carbonyl Source
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A novel and efficient approach for the C(sp2)-H bond carbonylation of benzamides has been developed using stable and inexpensive Co(OAc)2·4H2O as the catalyst and the commercially available and easily handling azodicarboxylates as the nontoxic carbonyl source. A broad range of substrates bearing diverse functional groups were tolerated. This is the first example where cobalt-catalyzed C(sp2)-H bond carbonylation occurs with azodicarboxylate as the carbonyl source.
- Ni, Jiabin,Li, Jie,Fan, Zhoulong,Zhang, Ao
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supporting information
p. 5960 - 5963
(2016/11/29)
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- Process for the preparation of 4`-haloalkylbiphenyl-2-carboxylic acids
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The invention relates to a process for the preparation of optionally substituted 4′-haloalkyl-biphenyl-2-carboxylic acid esters and to a process for the preparation of corresponding optionally substituted 4′-haloalkylbiphenyl-2-carboxylic acids.
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Page/Page column 6
(2012/02/01)
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- Ring-opening of cyclic anhydrides using ionic liquids
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Four novel Bronsted acidic ionic liquids with two different acid sites on the imidazolium cations were synthesised and employed as catalysts and solvents for the ring-opening of cyclic anhydrides to synthesise half-esters. The results showed that these novel Bronsted acidic ionic liquids were efficient and recyclable. Good yields, short reaction times and mild reaction conditions were achieved.
- Jiang, Dong,Wang, Yuan Yuan,Xu, Yan Nan,Dai, Li Yi
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experimental part
p. 167 - 169
(2009/10/15)
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- Monitoring of phthalic acid monoesters in river water by solid-phase extraction and GC-MS determination
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An analytical method for monitoring 10 phthalic acid monoesters in river water was investigated by solid-phase extraction, methylation with diazomethane, and GC-MS. Two cartridge-type solid phases packed with octadesyl-coated silica (C18) and styrenedivinyl polymer (PS-2) and one disk-type solid phase made from octadesyl-coated styrene-divinylbenzene polymer (SDB-XD) were investigated in solid-phase extraction. PS-2 gave the highest recoveries of the three solid phases, and recoveries of more than 80% of the monoesters in filtered water samples were obtained at pH 2 to 3 with PS-2 at the spiked level of 0.1 μg L-1, except for monomethyl-phthalate (MMP), in which more than 72% of the monoesters were recovered. For the monoesters in the suspended solids (SS), an acidic methanol extract of SS was added to purified water acidified to pH 2, and the monoesters were extracted with PS-2. The recoveries of the monoesters in SS were more than 80%, but the recoveries of MMP were more than 57%. The method detection limit (MDL) of each phthalic acid monoester in 500 mL of water sample and in 2 mg of dry weight of SS ranged from 0.010 to 0.030 μg L-1 and from 1 to 11 μg g-1 respectively. Monitoring of phthalic acid monoesters in the Tama River in Tokyo was conducted every month from March 1999 to February 2000 using the present method. MMP, mono-n-butyl-phthalate (MBP), and mono-(2-ethylhexyl)-phthalate (MEHP) were detected at concentrations of 0.030-0.0340, 0.010-0.480, and 0.010-1.30 μg L-1. respectively, in the filtered water samples but were not detected in SS. Dimethyl-phthalate (DMP), di-n-butyl-phthalate (DBP), and di-(2-ethylhexyl)-phthalate (DEHP) were detected in the river water at concentrations of 0.010-0.092, 0.008-0.540, and 0.013-3.60 μg L-1, respectively. Diethyl-, di-iso-butyl-, and benzylbutyl-phthalates were also detected at concentrations of nanograms per liter, whereas the corresponding monoesters did not appear. The concentrations of MBP and MEHP in the river water were slightly lower than those of the corresponding diesters at the majority of sampling sites and sampling times.
- Suzuki,Yaguchi,Suzuki,Suga
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p. 3757 - 3763
(2007/10/03)
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- A new simplified method for esterification of secondary and tertiary alcohols
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Esters of secondary and tertiary alcohols have been synthetized in the absence of solvent and catalyst and only under the effect of temperature with high yields.
- Kammoun,Le Bigot,Delmas,Boutevin
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p. 2777 - 2781
(2007/10/03)
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- RATIO OF LYATE IONS ACTIVITIES IN TWO-COMPONENTS PROTOGENIC SOLVENTS
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Kinetic method for the evaluation of lyate ions activities in two-component protogenic solvents has been discussed.Spectral methods for the measurement of equilibria between alkoxide and hydroxide ions have been compared.A correlation between dissociation constants of water and of weak organic acids in solvent mixtures has been found.By means of this correlation, ratios of lyate ions activities in water-ethanol and water-propanol mixtures have been calculated.These activity ratios, together with the known composition of reaction products, have been used to evaluate the selectivity of the neutral and alkaline solvolysis of phthalic anhydride and benzyl chloride in solvent mixtures quoted above.
- Mollin, Jiri,Pavelek, Zdenek,Kasparek, Frantisek
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p. 1115 - 1130
(2007/10/02)
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