20347-65-3Relevant academic research and scientific papers
Formation of hemiacetal esters in lipase-catalysed reactions of vinyl esters with hindered secondary alcohols
H?gberg, Hans-Erik,Lindmark, Marica,Isaksson, Dan,Sj?din, Kristina,Franssen, Maurice C. R.,Jongejan, Hugo,Wijnberg, Joannes B. P. A.,De Groot, Aede
, p. 3193 - 3196 (2000)
Normally many lipases are efficient catalysts for the acetylation of alcohols with vinyl acetate. Unexpectedly, we found that some sterically hindered secondary alcohols react slowly to yield hemiacetal esters as mixtures of diastereomers. Their formation can be explained by the reaction of the alcohol with acetaldehyde that is produced by the lipase-catalysed splitting of vinyl acetate and subsequent acetylation of the resulting hemiacetal by the lipase. (C) 2000 Elsevier Science Ltd.
Synthesis and characterization of a new acid molten salt and the study of its thermal behavior and catalytic activity in Fischer esterification
Zaharani, Lia,Khaligh, Nader Ghaffari,Johan, Mohd Rafie,Gorjian, Hayedeh
, p. 7081 - 7088 (2021/05/03)
A new acid molten salt was prepared and its structure elucidation was conducted by FTIR, 1D NMR, 2D NMR, and mass spectrometry. Further support to elucidate the chemical structure of the 1H,4H-piperazine-N,N′-diium ring of the new acid molten salt was achieved by1H and13C NMR, and COSY analyses of 1H,4H-piperazine-N,N′-diium dibromide, which is synthesized and characterized for the first time in the current work. The analysis of FTIR and NMR spectra as well as pH and titrimetric analysis excluded the formation of [SO4]2?and the presence of an excess of H2SO4. Moreover, no distinguishing peak was detected for the acid proton of [HSO4]?in DMSO-d6. The thermal phase transition and thermal stability of the acid molten salt were also recorded, which approved the strong interaction between a dication and hydrogen sulfate anions. According to the acidity of the new molten salt, we encourage the study of its catalytic activity for the acetylation ofn-pentanol using glacial acetic acid. Pentyl acetate was obtained in 89.0% conversion and 78.0% isolated yield. The1H NMR spectrum of the residue showed an excess of HOAc together with molten salt, whereas the1H NMR spectrum of the upper phase exhibited pure pentyl acetate. After separation of the upper phase, the residue was concentrated and used in the next run without further purification. No significant changes in the chemical structure and catalytic activity of the new molten salt were observed even after the 5th run. Two chiral alcohols, including (?)-menthol and (+)-borneol, as well as α-tocopherol (α-TCP) were also acetylated with acetic acid in the presence of the new acid molten salt under optimized reaction conditions, which afforded the desired acetates in high yields.
Synthesis, Characterisation, and Determination of Physical Properties of New Two-Protonic Acid Ionic Liquid and its Catalytic Application in the Esterification
Shahnavaz, Zohreh,Zaharani, Lia,Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie
, p. 165 - 172 (2020/10/26)
A new ionic liquid was synthesised, and its chemical structure was elucidated by FT-IR, 1D NMR, 2D NMR, and mass analyses. Some physical properties, thermal behaviour, and thermal stability of this ionic liquid were investigated. The formation of a two-protonic acid salt namely 4,4′-trimethylene-N,N′-dipiperidinium sulfate instead of 4,4′-trimethylene-N,N′-dipiperidinium hydrogensulfate was evidenced by NMR analyses. The catalytic activity of this ionic liquid was demonstrated in the esterification reaction of n-butanol and glacial acetic acid under different conditions. The desired acetate was obtained in 62-88 % yield without using a Dean-Stark apparatus under optimal conditions of 10 mol-% of the ionic liquid, an alcohol to glacial acetic acid mole ratio of 1.3: 1.0, a temperature of 75-100°C, and a reaction time of 4 h. α-Tocopherol (α-TCP), a highly efficient form of vitamin E, was also treated with glacial acetic acid in the presence of the ionic liquid, and O-acetyl-α-tocopherol (Ac-TCP) was obtained in 88.4 % yield. The separation of esters was conducted during workup without the utilisation of high-cost column chromatography. The residue and ionic liquid were used in subsequent runs after the extraction of desired products. The ionic liquid exhibited high catalytic activity even after five runs with no significant change in its chemical structure and catalytic efficiency.
Method for synthesizing bornyl acetate from turpentine
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Paragraph 0036-0280, (2021/01/29)
The invention discloses a method for synthesizing bornyl acetate from turpentine, which relates to the technical field of deep processing of turpentine. The preparation method comprises the followingsteps of proportioning titanium sulfate and hydroxycarboxylic acid to form a composite catalyst, mixing turpentine, acetic acid and the composite catalyst, and reacting in a stirring state, after thereaction is finished, filtering, and removing acetic acid from the filtrate to obtain a solution containing bornyl acetate, neutralizing the solution containing the bornyl acetate, and washing with water to obtain a bornyl acetate crude product, and then fractionating the crude product of the bornyl acetate to obtain the bornyl acetate. The synthesis method provided by the invention is high in catalytic activity, low in cost and high in selectivity on the borneol acetate, and does not need to use a raw material with too high pinene content.
Simple Plug-In Synthetic Step for the Synthesis of (?)-Camphor from Renewable Starting Materials
Calderini, Elia,Drienovská, Ivana,Myrtollari, Kamela,Pressnig, Michaela,Sieber, Volker,Schwab, Helmut,Hofer, Michael,Kourist, Robert
, p. 2951 - 2956 (2021/06/18)
Racemic camphor and isoborneol are readily available as industrial side products, whereas (1R)-camphor is available from natural sources. Optically pure (1S)-camphor, however, is much more difficult to obtain. The synthesis of racemic camphor from α-pinene proceeds via an intermediary racemic isobornyl ester, which is then hydrolyzed and oxidized to give camphor. We reasoned that enantioselective hydrolysis of isobornyl esters would give facile access to optically pure isoborneol and camphor isomers, respectively. While screening of a set of commercial lipases and esterases in the kinetic resolution of racemic monoterpenols did not lead to the identification of any enantioselective enzymes, the cephalosporin Esterase B from Burkholderia gladioli (EstB) and Esterase C (EstC) from Rhodococcus rhodochrous showed outstanding enantioselectivity (E>100) towards the butyryl esters of isoborneol, borneol and fenchol. The enantioselectivity was higher with increasing chain length of the acyl moiety of the substrate. The kinetic resolution of isobornyl butyrate can be easily integrated into the production of camphor from α-pinene and thus allows the facile synthesis of optically pure monoterpenols from a renewable side-product.
4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis, structural analysis, physical properties and catalytic application as dual solvent-catalyst
Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie,Juan, Joon Ching
, p. 866 - 878 (2019/07/12)
4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (1H, 13C). The “plausible” alternative structures of ImBu-SO3H were discussed on the basis of its NMR data. The ionic liquid showed interesting dual solvent-catalyst property, which was studied experimentally for the acetylation of a variety of functionalized alcohols, phenols, thiols, amines and α-tocopherol (α-CTP) as the most active form of vitamin E with acetic anhydride and which provided good yields within a short reaction time. ImBu-SO3H was successfully recycled by product extraction with an average recovered yield of 82% for 5 subsequent runs. The catalytic activity of the recycled ImBu-SO3H showed almost no loss even after five consecutive runs.
Heterogeneous zeolite-based catalyst for esterification of α-pinene to α-terpinyl acetate
Wijayati, Nanik,Kusumastuti, Ella,Alighiri, Dante,Rohmawati, Baiti,Lusiana, Retno Ariadi
, p. 399 - 403 (2019/06/05)
The purpose of this study is to determine the most effective type of heterogeneous catalyst such as natural zeolite (ZA), Zr-natural zeolite (Zr/ZA) and zeolite Y (H/ZY) in esterification of α-pinene. α-terpinyl acetate was successfully synthesized from α-pinene and acetic anhydride by their heterogeneous catalysts. The esterification reaction was carried out with reaction time, temperature and zeolite catalysts. The most effective catalysts used in the synthesis of α-terpinyl acetate is catalyst H/ZY with the yield is 52.83% at 40oC for the time 4 h with a selectivity of 61.38%. The results showed that the effective separation of catalyst could contribute to developing a new strategy for the synthesis of α-terpinyl acetate.
Method for synthesizing isobornyl acetate by camphene
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Page/Page column 5-13, (2018/12/13)
The invention discloses a method for synthesizing isobornyl acetate by camphene. The method comprises the following steps of adding camphene, glacial acetic acid, a main catalyst (hydroxycarboxylic acid) and an additive into a reaction kettle according to a mass ratio of 100:(20 to 400):(1 to 50):(1 to 20), starting to stir, controlling the temperature to 40 to 100 DEG C, and reacting for 2 to 24h, so as to obtain a synthesized product; adding a small amount of water into the synthesized product, standing and delaminating, wherein the upper oil layer is a target product containing isobornyl acetate, the lower layer is acid water containing the catalyst and acetic acid, and the acid water is dewatered and recycled; adding the target product into a water washing tank, adding alkaline water to neutralize, and then adding water to wash, so as to obtain a crude product of the isobornyl acetate; relieving pressure and distilling, so as to obtain the refined isobornyl acetate. The method forsynthesizing the isobornyl acetate by catalyzing the camphene has the advantages that the obtained product has high yield and high purity, and is easy to separate; the used catalyst has high catalyzing activity; the preparation is simple, the repeatability is good, the toxicity is avoided, the corrosion property is low, the isobornyl acetate belongs to regeneration resources, and the industrialization product is easy.
Rice husk ash: A new, cheap, efficient, and reusable reagent for the protection of alcohols, phenols, amines, and thiols
Shirini,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali
, p. 577 - 586 (2014/06/09)
Amild, efficient, and eco-friendly protocol for the protection of alcohols and phenols as trimethylsilyl ethers has been developed using rice husk ash as a reagent. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols, and amines with acetic anhydride. All reactions were performed under mild conditions in good to high yields. Copyright
Preparation, characterization and use of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid phase catalyst for acetylation of alcohols, phenols and amines
Khaligh, Nader Ghaffari
, p. 90 - 100 (2012/11/06)
Poly(4-vinylpyridine) perchlorate, is a supported, recyclable, eco-benign catalyst for the reaction acetylation of structurally diverse alcohols, phenols and amines at room temperature under solvent-free conditions. The catalyst was studied by FT-IR, X-ray diffraction, Scanning Electron Microscope and Thermo-gravimetric Analyses. All the products were extensively characterized by 1H NMR, FT-IR, GC-MS and melting point analyses. The catalyst can be recovered and reused without loss of activity. The work-up of the reaction consists of a simple filtration, followed by concentration of the crude product and purification. It is important to point out that a large-scale reaction is possible using a same amount of catalyst.
