- N-Heterocyclic carbene-catalyzed synthesis of acetyltributylcitrate via a transesterification reaction
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A new methodology for the synthesis of a green plasticizer acetyltributylcitrate through a transesterification reaction was developed. Under the catalysis of alkyl-substituted imidazol-type N-heterocyclic carbenes, tributyl citrate can react with vinyl acetate smoothly to give ATBC in high yield.
- He, Lin,Guo, Hao,Ma, Xiao-Wei,Zhang, Jie,Gu, Cheng-Zhi,Wang, Wei,Dai, Bin
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Read Online
- A composite solid acid for catalytic synthesis of acetyl tributyl citrate process
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A technology for synthesizing ATBC (acetyl tributyl citrate) under catalysis of composite solid acid comprises steps as follows: citri acid anhydrous and n-butyl alcohol are added to a reactor, a catalyst is added, the mixture reacts for 3-6 hours at the temperature of 120 DEG C-160 DEG C, and TBC (tributyl citrate) is synthesized and dealcoholized; acetic anhydride is added to dealcoholized TBC and reacts for 1-2 hours at the temperature of 60 DEG C-100 DEG C, the catalyst is obtained through filtering after a reaction liquid is cooled, water is added to filtrate, acetic anhydride is hydrolyzed, acetic acid is recovered through deacidification, and an ATBC finished product is prepared through aftertreatment. Defects of a complicated technology, long production period, high product loss, numerous three wastes, environmental pollution and the like of an existing preparation method of ATBC are overcome; the catalyst is simple to prepare and easy to separate and recover and can be recycled without treatment.
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Paragraph 0029
(2017/01/02)
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- An imidazolium tosylate salt as efficient and recyclable catalyst for acetylation in an ionic liquid
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A novel non-metallic salt, 1-butyl-3-methylimidazolium tosylate ([bmim][OTs]) dissolved in the ambient temperature ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), was found to be the efficient catalyst for acetylation with the advantages of good recyclability, avoidance of metal contamination, mild reaction conditions, and wide availability for substrates (alcohols, phenols, and amines), could completely replace organic bases, metal Lewis acids, or metallic triflates to fulfill acetylation by a nucleophilic catalytic mechanism, which was supported by 13C NMR analysis.
- Liu, Ye,Liu, Lu,Lu, Yong,Cai, Yue-Qin
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experimental part
p. 633 - 638
(2009/08/07)
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- Widely useful DMAP-catalyzed esterification under auxiliary base- and solvent-free conditions
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With regard to atom economy and E-factor, catalytic condensation of carboxylic acids with equimolar amounts of alcohols is the most desirable. Although several highly active dehydration catalysts have been reported, more efficient alternatives are still strongly needed because the dehydrative esterification of tertiary alcohols, phenols, acid-sensitive alcohols, amino acids, and hardly soluble alcohols has never proceeded satisfactorily. Here we report new insights into the classical DMAP-catalyzed acylation of alcohols: surprisingly, only a 0.05-2 mol % of DMAP can efficiently promote acylation of alcohols with acid anhydrides under auxiliary base- and solvent-free conditions to give the corresponding esters in high yields. Furthermore, we achieved the recovery and reuse of commercially available polystyrene-supported DMAP without using any solvents. These serendipitous findings provide widely useful and environmentally benign esterification methods, which might be more practical and reliable than catalytic dehydrative condensation methods, in particular, for the less reactive alcohols which hardly condense with carboxylic acid directly.
- Sakakura, Akira,Kawajiri, Kimio,Ohkubo, Takuro,Kosugi, Yuji,Ishihara, Kazuaki
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p. 14775 - 14779
(2008/09/17)
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