2052-14-4Relevant academic research and scientific papers
Ultrasound-assisted third-liquid phase-transfer catalyzed esterification of sodium salicylate in a continuous two-phase-flow reactor
Yang, Hung-Ming,Peng, Guan-Yi
, p. 239 - 245 (2010)
The esterification of sodium salicylate to synthesize butyl salicylate by third-liquid phase-transfer catalysis under ultrasound irradiation was investigated in a continuous two-phase-flow reactor. The reactor was designed to keep the third-liquid phase in the middle part and to have the aqueous and organic phases flowing through it in countercurrent. Using tetra-n-butylphosphonium bromide to prepare the third-liquid phase for this esterification, the product yield in the organic outlet (toluene) at 70 °C was 49.7% in silent condition, showing the reaction promoted simply by countercurrent mixing of the aqueous and organic phases. In the conditions of space time at 168 min, stirring at 150 rpm and ultrasound irradiation (28 kHz, 300 W), the product yield was greatly enhanced to 78.2%. As prepared, above 90% of the added catalyst existed in the third-liquid phase, and after 4-h on stream for a large excess of n-butyl bromide to sodium salicylate, the fraction of catalyst retaining in the reactor was reduced to around 80%. The distributions of catalysts between phases before and after reaction were analyzed. A kinetic model was proposed to estimate the apparent rate constants, and the feasibility for third-liquid phase-transfer catalysis assisted by ultrasound irradiation in a continuous flow reactor was demonstrated.
Synthesis of salicylates from anionically activated aromatic trifluoromethyl group
Lin, Chuankai,Liu, Jin-Biao,Wang, Ruixiang,Xie, Huilin
supporting information, (2021/12/22)
An efficient approach to salicylates via a novel transformation of anionically activated aromatic trifluoromethyl group is described. Anionically activated trifluoromethyl group can react with phenols/alcohols under alkaline conditions to afford aryl/alkyl salicylates in high yields. Mechanism studies indicate that the carbonyl oxygen atom of ester is from the H2O in the solvent.
Robust acidic pseudo-ionic liquid catalyst with self-separation ability for esterification and acetalization
Shi, Yingxia,Liang, Xuezheng
, p. 1413 - 1421 (2019/05/04)
The novel acidic pseudo-ionic liquid catalyst with self-separation ability has been synthesized through the quaternization of triphenylphosphine and the acidification with silicotungstic acid. The pseudo-IL showed high activities for the esterification with average conversions over 90%. The pseudo-IL showed even higher activities for acetalization than traditional sulfuric acid. The homogeneous catalytic process benefited the mass transfer efficiency. The pseudo-IL separated from the reaction mixture automatically after reactions, which was superior to other IL catalysts. The high catalytic activities, easy reusability and high stability were the key properties of the novel catalyst, which hold great potential for green chemical processes.
Single-Step Dual Functionalization: One-Pot Bromination-Cross-Dehydrogenative Esterification of Hydroxy Benzaldehydes with CCl 3 Br - A Comparison with Selectfluor
Talukdar, Ranadeep
supporting information, p. 1713 - 1718 (2019/08/28)
Bromination of phenolic compounds without directly using molecular bromine possesses much importance. In this article an Ir III /CCl 3 Br-assisted single-step double functionalization of hydroxy benzaldehydes is reported. It involves simultaneous esterification of the aldehyde group and bromination of the aryl ring of phenolic aldehydes in one-pot. The reaction proceeds under mild conditions in the presence of 445 nm blue LED light to obtain highly functionalized bromo hydroxy benzoates in moderate to good yields. In comparison, Selectfluor as an oxidant gives only non-bromo phenolic esters.
Synthesis of Hydroxybenzoic Acids and Their Esters by Reaction of Phenols with Carbon Tetrachloride and Alcohols in the Presence of Iron Catalysts
Bayguzina,Tarisova,Khusnutdinov
, p. 208 - 215 (2018/03/26)
Alkyl esters of hydroxy-, methoxy-, and ethoxybenzoic and cresotic acids have been synthesized by reaction of phenols, anisole, phenetole, and cresols with carbon tetrachloride and alcohols in the presence of iron catalysts.
Synthesis and structures of 1,2,4-triazoles derivatives
Wang, Ning,Sheng, Jun-Feng,Song, Fei,Tong, Yu-Zhu,Wang, Zuo-Xiang
, p. 746 - 751 (2015/05/05)
Abstract A series of novel 1,2,4-triazole derivatives were synthesized, and their structures were characterized by IR, UV-Vis, FL, NMR, ESI-MS, and elemental analysis. In the meanwhile, the single crystal structures of 3,4-diethyl-5-(4-pyridyl)-1,2,4-triazole and 3,4-dimethyl-5-(o-hydroxyphenyl)-1,2,4-triazole were determined by X-ray diffraction.
Enhancement of optical faraday effect of nonanuclear Tb(III) complexes
Nakanishi, Takayuki,Suzuki, Yuki,Doi, Yoshihiro,Seki, Tomohiro,Koizumi, Hitoshi,Fushimi, Koji,Fujita, Koji,Hinatsu, Yukio,Ito, Hajime,Tanaka, Katsuhisa,Hasegawa, Yasuchika
, p. 7635 - 7641 (2014/08/05)
The effective magneto-optical properties of novel nonanuclear Tb(III) complexes with Tb-O lattice (specifically, [Tb9(sal-R) 16(μ-OH)10]+NO3-, where sal-R = alkyl salicylate (R = -CH3 (Me), -C2H 5 (Et), -C3H7 (Pr), or -C4H 9 (Bu)) are reported. The geometrical structures of these nonanuclear Tb(III) complexes were characterized using X-ray single-crystal analysis and shape-measure calculation. Optical Faraday rotation was observed in nonanuclear Tb(III) complexes in the visible region. The Verdet constant per Tb(III) ion of the Tb9(sal-Me) complex is 150 times larger than that of general Tb(III) oxide glass. To understand their large Faraday rotation, electron paramagnetic resonance measurements of Gd(III) complexes were carried out. In this Report, the magneto-optical relation to the coordination geometry of Tb ions is discussed.
SO3H-functionalized Bronsted acidic ionic liquids as efficient catalysts for the synthesis of isoamyl salicylate
Tao, Duan-Jian,Wu, Jing,Wang, Zhen-Zhen,Lu, Zhang-Hui,Yang, Zhen,Chen, Xiang-Shu
, p. 1 - 7 (2014/01/06)
Six Bronsted acidic ionic liquids (BAILs) composed of [HSO 4] were prepared, characterized, and used as catalysts of low dosage in the synthesis of isoamyl salicylate. The effects of various parameters such as the kind of BAILs, temperature, catalyst loading, and molar ratio of the reactants on the conversion of salicylic acid were also examined in detail. The results suggested that the catalytic performances of BAILs were of close relevance to their Hammett acidities. The SO3H-functionalized BAILs 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate ([BSmim][HSO 4]) and N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate ([BSEt3N][HSO4]) of strong acidities exhibited excellently catalytic activities and selectivities in the esterification of salicylic acid with isoamyl alcohol. The fully optimized geometries of [BSmim][HSO4] and [BSEt3N][HSO4] further manifest that their strong acidities are derived from the strong interactions between the anion with the sulfonic acid group. In addition, it was found that [BSmim][HSO4] could be also recovered easily and used repetitively at least six times without obvious decline in activity and quantity.
Esterification of salicylic acid using Br?nsted acidic ionic liquid based on Keggin heteropoly acid
Bamoharram, Fatemeh F.,Heravi, Majid M.,Ebrahimi, Javad,Tavakoli-Hoseini, Nilofar
, p. 36 - 42 (2016/09/23)
For the first time, a newwater stable Br?nsted acidic ionic liquid based on Keggin heteroployacid (HPA) was used as environmentally benign catalytic medium in the esterfication of salicylic acid with aliphatic alcohols, CnH2n+1OH (n = 1-5) and benzylic alcohols, RC6H4CH2OH (R = H, NO2, OCH3). This ionic liquid (IL) afforded excellent yield in both thermal conditions and microwave irradiation. Maximum yields were observed under microwave irradiation. Different reaction runs were conducted by varying the reaction parameters such as molar ratio of reactants, weight of the IL, and reaction period in order to optimize the reaction. The IL was easily recovered and reused many times. No significant loss in catalytic activity was observed on recycling.
Esterification of salicylic acid using Ce4+ modified cation-exchange resin as catalyst
Zhang, Ming,Zhu, Wen Shuai,Li, Hua Ming,Shi, Hua,Yan, Yong Sheng,Wang, Zhi Gao
, p. 1477 - 1481 (2013/07/19)
The esterification of salicylic acid with methanol was carried out over a series of Ce4+ modified cation-exchange resins. The effect of different reaction conditions was studied on the conversion of salicylic acid, and the optimal reaction parameters were obtained. The experimental results indicated that Ce(SO4)2/001×7 was an effective catalyst for the synthesis of methyl salicylate. The conversion of salicylic acid could reach 93.3% while its selectivity was more than 99.0%. SEM-EDS and TG-DSC analysis were employed to characterize the structure and property of the catalyst. Besides, the catalytic performance of Ce(SO4) 2/001×7 in the esterification of salicylic acid with different alcohols was compared. The reusability of Ce(SO4)2/ 001×7 was also studied by using salicylic acid and methanol as model substrates. The mechanism was proposed for the esterification of salicylic acid with methanol over Ce4+ modified cation-exchange resins.
