131-16-8Relevant articles and documents
Functionalized dicationic ionic liquids: Green and efficient alternatives for catalysts in phthalate plasticizers preparation
Zekri, Negar,Fareghi-Alamdari, Reza,Khodarahmi, Zahra
, p. 1277 - 1284 (2016)
Two highly acidic, imidazolium-based, functionalized dicationic ionic liquids (FDCILs) were synthesized and characterized by FTIR, 1H NMR and13C NMR. The synthesized FDCILs were used as efficient and green catalysts in the synthesis of phthalate plasticizers through esterification of phthalic anhydride (PhA) with ethanol, n-propanol and n-butanol. Among these two FDCILs, (dimethyl-4-sulfobutyl-ammonium) 1,2-ethan-1-methyl-imidazolium-sulfonic acid hydrogen sulfate performed better. The catalytic activity of FDCIL is related to the density of acidic groups on it and the length of the carbon chain in the cationic part. The influences of the reaction temperature, catalyst dosage, and molar ratio of phthalic anhydride to alcohol on the esterification reaction were investigated. The reusability of the catalyst in these reactions was studied too. The diester phthalates were obtained up to 98.8% yield. The products can be separated easily by decantation from the reaction mixture. [Figure not available: see fulltext.]
A novel hydrogen-bonded silica-supported acidic ionic liquid: An efficient, recyclable and selective heterogeneous catalyst for the synthesis of diesters
Fareghi-Alamdari, Reza,Niri, Mehri Nadiri,Hazarkhani, Hassan
, (2018/05/28)
Abstract: In this study, two novel acidic ionic liquids, including a hydroxyl functionalized diacidic ionic liquid [HFDAIL] and a sulfonated diacidic ionic liquid [SFDAIL], were prepared and immobilized on the surface of silica nanoparticles (SNPs) via hydrogen bonding. The materials were characterized by FT-IR, NMR, SEM, nitrogen physisorption measurement, TGA and acid-base titration. The catalytic activity of the prepared catalysts was investigated in the synthesis of phthalate, maleate and succinate diesters under solvent-free conditions. It was found that nanosilica@[HFDAIL] with higher availability of acidic sites and higher hydrophilicity was more efficient compared to the nanosilica@[SFDAIL]. Notably, nanosilica@[HFDAIL] catalyst has also demonstrated excellent selectivity for the diester product while the monoester product was predominant in the case of nanosilica@[SFDAIL] even after prolonged reaction time or higher catalyst loading. In addition, the nanosilica@[HFDAIL] catalyst could be separated by simple filtration and reused several times without any significant loss of catalytic performance, but a remarkable decrease in activity was observed for nanosilica@[SFDAIL] in the next runs. GRAPHICAL ABSTRACT?: SYNOPSIS Two novel acidic ionic liquids, including a hydroxyl functionalized diacidic ionic liquid [HFDAIL] and a sulfonated diacidic ionic liquid [SFDAIL], were prepared and immobilized on the surface of silica nanoparticles via hydrogen bonding. The catalytic activity of the catalysts was investigated in the synthesis of diesters under solvent-free conditions.
Facile esterification of carboxylic acid using amide functionalized benzimidazolium dicationic ionic liquids
Muskawar, Prashant Narayan,Thenmozhi,Gajbhiye, Jayant M.,Bhagat, Pundlik Rambhau
, p. 214 - 220 (2014/07/08)
Herein, we report the synthesis of a new series of amide functionalized dicationic benzimidazolium based ionic liquids (DBimILs) and appraised their efficacy towards perceptive esterification of carboxylic acids with alkyl/allyl/aryl halides in presence of triethylamine. The amide groups present in this new series of DBimILs are expected to form hydrogen bonding with the carboxylic acids and this could facilitate the esterification reactions under mild conditions devoid of any added catalyst or organic solvent. The plausible mechanism for the enhanced catalytic activity in presence of this new series of ILs has been proposed. The corresponding alkyl/allyl/aryl esters isolated from this reaction were of high purity after simple extraction, which wipe out the necessity for further purification. This protocol addresses clean methodology and the efficient recyclability as well as reusability of the catalyst.
