- Synthesis and characterization of a new acid molten salt and the study of its thermal behavior and catalytic activity in Fischer esterification
-
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.
- Zaharani, Lia,Khaligh, Nader Ghaffari,Johan, Mohd Rafie,Gorjian, Hayedeh
-
p. 7081 - 7088
(2021/05/03)
-
- SYNTHESIS OF CHROMANOL AND 2-METHYL-1,4-NAPHTHOQUINONE DERIVATIVES
-
The present invention relates to a process for the production of chromanol and 2-methyl-1,4-naphthoquinone derivatives, more specifically to a process for preparing a compound of the general formula (I) or (II) wherein the variables are as defined in the claims and the description.
- -
-
-
- 4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis, structural analysis, physical properties and catalytic application as dual solvent-catalyst
-
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.
- Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie,Juan, Joon Ching
-
p. 866 - 878
(2019/07/12)
-
- Method for preparing vitamin E acetate
-
The invention provides a method for preparing vitamin E acetate. The method has the characteristic of high product selectivity; a catalyst used in the method provided by the invention facilitates recovery and reutilization and has less corrosion to equipment; and a product has good stability. The method for preparing the vitamin E acetate provided by the invention prepares the vitamin E acetate through a reaction of 2,3,5-trimethylhydroquinone diester and isophytol, wherein the reaction is carried out in the presence of the catalyst; and with a molecular sieve as a carrier, the catalyst is prepared by loading Bronsted acid, metal halide, metallocene and a metal element onto the molecular sieve.
- -
-
Paragraph 0068; 0069; 0070; 0071; 0073
(2019/05/15)
-
- Vitamin E acetate preparation method (by machine translation)
-
The invention relates to a technical field of chemical synthesis, in particular relates to a vitamin E acetate preparation method, in order to trimethyl [...][...] as raw materials, innovative in a sulfuric acid and paratoluene sulfonic acid under acidic conditions, using magnesium sulfate as a catalyst, greatly improves the catalytic efficiency; in addition, in concentrated hydrochloric acid and ethyl acetate under the reaction environment, esterification synthetic vitamin E acetate efficiency is higher; and, synthetic route of this invention relates to the reaction of the routine chemical reaction, mild reaction conditions, simple operation, is suitable for industrial. (by machine translation)
- -
-
Paragraph 0013
(2019/01/06)
-
- Method of preparing vitamin E acetate
-
The invention provides a method of preparing vitamin E acetate. The method includes the steps of: feeding hydrogen halide gas as a catalyst, supporting a metal halide and elementary metal on a molecular sieve to obtain a cocatalyst and a stabilizing agent, and performing a reaction to 2,3,5-trimethylhydroquinone diester (TMHQ-DA) and iso-phytol (IPL) to produce the vitamin E acetate (VEA). The method has high catalyst activity and has low corrosion on equipment, wherein the raw material is converted into the vitamin E acetate directly through one step. The product has good stability and the method is easy to carry out in industrial enlarged production.
- -
-
Paragraph 0065; 0066; 0069
(2017/05/13)
-
- Clean production method of vitamin E acetate
-
The invention discloses a clean production method of vitamin E acetate. The method comprises the following steps: (1) an esterification reaction is carried out for tocopherol and acetic anhydride in the existence of a solvent with DMAP as a catalyst, after the reaction completely ends, the solvent is removed by steaming, an acid is added for adjusting the pH value to 5-7, water is added for washing, and delamination is carried out in order to obtain a water layer and an organic layer; (2) distillation is carried out for the organic layer, distillate and raw oil are obtained, refining is further carried out for the raw oil, and a vitamin E acetate finished product is obtained. The clean production method improves yield of the reaction, reduces application amount of the catalyst, and more importantly reduces discharge capacity of waste water obviously.
- -
-
Paragraph 0026; 0027
(2016/12/26)
-
- Using imidazolium-based ionic liquids as dual solvent-catalysts for sustainable synthesis of vitamin esters: Inspiration from bio- and organo-catalysis
-
Vitamin E (VE) has significant biological activities and thus its acylation to increase its stability is of extreme interest. We developed an efficient and sustainable approach using imidazolium-based ionic liquids as dual solvent-catalysts for the esterification between α-tocopherol (the most active form of VE) and succinic anhydride. Although in literature it is reported that lipase can catalyze this reaction, hereby we demonstrate that the reaction observed in DMSO and DMF is catalyzed by the histidyl residues of the protein. Histidine and its analogue containing an imidazole ring were tested as organocatalysts for the production of α-tocopherol succinate. In light of the imidazole organocatalysis, commercially-available 3-alkyl-1-methyl imidazolium ILs [CnC1Im][X-] were investigated as dual solvent-catalysts for the esterification of α-tocopherol with succinic anhydride, and provided satisfactory yields and reaction rates. [C5C1Im][NO3-] can be recycled by water extraction, instead of organic solvent extraction to separate α-tocopherol succinate from [C5C1Im][NO3-], with an average yield of 94.1% for 4 subsequent batches, while the catalytic activity of the recycled ILs showed almost no loss after 4 batches. The developed protocol for the synthesis of α-tocopherol esters and IL recycling bears industrial potential due to the ease of use and the efficient recycling.
- Tao, Yifeng,Dong, Ruijuan,Pavlidis, Ioannis V.,Chen, Biqiang,Tan, Tianwei
-
supporting information
p. 1240 - 1248
(2016/03/09)
-
- dl-alpha tocopherol acetate preparation method
-
The present invention relates to a dl-alpha tocopherol acetate preparation method, wherein trimethyl hydroquinone diethyl ester or trimethyl hydroquinone-4-ethyl ester is adopted as a raw material, Bronsted acid and Lewis acid are adopted as catalysts, the raw material and phytol or isophytol or a phytol derivative are directly subjected to a condensation reaction in an ester solvent to obtain the product dl-alpha tocopherol acetate or an intermediate dl-alpha tocopherol, wherein the intermediate dl-alpha tocopherol is subjected to further esterification to obtain the product dl-alpha tocopherol acetate. According to the present invention, the process route is simple, the production cost is reduced, the quality of the obtained product is good, the yield is high, and the method is suitable for large-scale industrial production.
- -
-
Paragraph 0040; 0041; 0042; 0043; 0044; 0045
(2016/10/24)
-
- Method for preparing d1-alpha tocopheryl acetate
-
The invention relates to a method for preparing d1-alpha tocopheryl acetate. According to the method, d1-alpha tocopherol or a mixture of d1-alpha tocopherol and d1-alpha tocopheryl acetate serves as a raw material, nitrogen-containing alkaline matter is adopted as a catalyst, acetic acid or acetic anhydride or a mixture of acetic acid and acetic anhydride serves as an acylating agent, and a d1-alpha tocopheryl acetate product is obtained through an esterification reaction. The preparation method is simple as a whole, operability is good, the yield is high, product quality is good, and besides risks in the aspects of the environment and safety are small.
- -
-
Paragraph 0033; 0034
(2016/11/14)
-
- ACYLATIONS IN MICRO REACTION SYSTEMS
-
A method for acylating tertiary alcohols and phenolic compounds with carboxylic acids or their anhydrides in micro-reaction systems wherein the acylation is effected in the absence of any catalyst including water at residence times of at most 30 minutes.
- -
-
Page/Page column 11-12
(2011/08/04)
-
- Iridium-catalyzed asymmetric hydrogenation of unfunctionalized, trialkyl-substituted olefins
-
Chiral iridium complexes with bicyclic pyridine-based N,P ligands have emerged as efficient catalysts for the enantioselective hydrogenation of unfunctionalized trialkyl-substituted olefins. Optimization of the reaction conditions by variation of the solvent, pressure, and temperature led to enantiomeric excesses of up to 99%. Three pure alkenes, (E)-2-cyclohexyl-2- butene and (E)- and (Z)-3,4-dimethyl-2-pentene were converted into the corresponding chiral alkanes with 97%, 94%, and 93% ee, respectively. Hydrogenation of the three C=C bonds of both α- and γ-tocotrienyl acetate led to α- and γ-tocopheryl acetate with very high diastereoselectivity. The same catalysts were successfully applied in the hydrogenation of trisubstituted alkenes with a carboxylic ester or a keto group in the γ position. This reaction was used as a key step in a highly enantioselective synthesis of the pheromone of the caddisfly Hesperophylax occidentalis. The hydrogenation of a structurally analogous allylic alcohol also gave high enantioselectivities. Unfunctionalized trialkyl-substituted olefins are hydrogenated with high efficiency and excellent enantioselectivity using iridium complexes derived from chiral N,P ligands. In this way, pharmaceutically interesting and industrially relevant compounds with chiral alkyl fragments are easily accessible with high diastereo- and enantioselectivities. Copyright
- Wang, Aie,Fraga, Rui P. A.,Hoermann, Esther,Pfaltz, Andreas
-
experimental part
p. 599 - 606
(2011/10/12)
-
- A Convenient access to (All-rac)-α-tocopherol acetate from linalool and dihydromyrcene
-
Refluxing trimethylhydroquinone 2 in 10:1 dodecane/CH2Cl 2 with linalool 3b (two-fold excess) and camphorsulfonic acid, then treating the crude condensation product (consisting of a mixture of the chromanols 1b and 1c, alongside the tricyclic compounds 9 and 10) sequentially with Ac2O and m-CPBA afforded, after removal by column chromatography of the 9/10 acetates, a mixture of the regioisomeric epoxides 1jOAc and 1kOAc (ratio 9:1, total 60%). Treatment of this mixture with Al(O-i-Pr)3 followed by CuI-catalysed Wurtz coupling of the acetates of the resulting allylic alcohols with citronellylmagnesium chloride 12a, and finally hydrogenation then provided the title acetate (overall 46% from 2).
- Gembus, Vincent,Sala-Jung, Nathalie,Uguen, Daniel
-
experimental part
p. 829 - 842
(2009/12/25)
-
- Biomimetic chromanol cyclisation: A common route to a-tocotrienol and α-tocopherol
-
A common synthetic route to a-tocotrienol and a-tocopherol has been accomplished by a biomimetic cyclisation that yields the chromanol ring. The chirality at C2 of the chro- manol was induced by a covalently attached chiral dipeptide. Its terminal Asp participates in the enantioface-selective pro-tonation of the double bond of the a-tocotrienol precursor. a-Tocotrienol was diastereoselectively hydrogenated to a-tocopherol.
- Chapelat, Julien,Chougnet, Antoinette,Woggon, Wolf-D.
-
experimental part
p. 2069 - 2076
(2009/09/08)
-
- Process for the working-up of a vitamin E- and vitamin E-acetate- containing mixture or products stream
-
The invention relates to a process for the working-up of a vitamin E (VE)- and/or vitamin E acetate (VEA)-containing product stream, which is substantially characterized by purification of a vitamin E-containing product stream, acetylation of at least a part of the purified vitamin E and purification of at least a part of the acetylated vitamin E, the purification of vitamin E and vitamin E acetate preferably being effected by distillation, for example rectification. A preferred process according to the invention is characterized in that a vitamin E-containing product stream is fed to a first rectification column (105), low-boiling products and unspecified isomers of vitamin E being taken off at the top (105a) of this first rectification column virtually without loss of useful substance, and a purified, vitamin E-containing stream being taken off at the side (105b) and/or at the bottom (105c) of the rectification column (105), at least a part of the side take-off or of the bottom take-off or at least a part of the side and bottom take-off is passed, for acetylation of vitamin E, into an acetylation stage (111), at least a part of the product stream emerging from the acetylation stage is passed into a second rectification column (115) or is taken off as useful product having a purity of ≧92% by weight, and in a second rectification column, the VEA useful product is obtained as a side take-off having a purity of ≧97% by weight.
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Page/Page column 5
(2009/12/05)
-
- Process For the Rectification of Mixtures of High-Boiling Air-and/or Temperature-Sensitive Useful Products
-
According to the invention, a process for the rectification of mixtures of high-boiling air- and/or temperature-sensitive substances which require a high separation efficiency is proposed, in particular a process for the working-up of a VE- or VEA-containing product stream. The process is characterized in particular in that, in a first purification stage, low-boiling products and unspecified isomers of the useful product are separated from the product stream virtually without loss of useful product and that, in a second purification stage, the useful product is removed in a stream having a purity of >97% by weight and a further stream having a purity of >92% by weight. A preferred embodiment of the process serves for working up VEA, in which the loss of useful product in the first purification stage is less than 5%, based on that amount of VEA in the feed which is added to the purification stage per unit time. Furthermore, the first purification stage may comprise a rectification column (1), from the top (Ia) of which the low-boiling products and the unspecified isomers of VEA are taken off, a stream containing the useful product in purified form being taken off at the side (15) and/or at the bottom (Ib) of the column (1).
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-
Page/Page column 4
(2008/12/07)
-
- METHOD OF MAKING PURIFIED ODOR FREE TOCOPHEROL ACETATE
-
A process for producing odor free tocopherol acetate is disclosed. This process comprises forming a solution of tocopherol acetate in a suitable solvent, e.g., isopropyl alcohol, subjecting said solution to a sufficient amount of low pressure and heat to remove said solvent and sparging sufficient amount of an inert gas through said solution to remove traces of remaining solvent.
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-
Page/Page column 1-2
(2008/12/06)
-
- PROCESS FOR THE ACYLATION OF ORGANIC HYDROXY COMPOUNDS
-
A process for acylating organic hydroxy compounds, characterized in that the acylation is effected in the presence of a metal oxide which does not carry a catalyst and the use of such metal oxides for acylating organic hydroxy compounds.
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-
Page/Page column 6-8
(2008/12/06)
-
- A highly selective, high-speed, and hydrolysis-free O-acylation in subcritical water in the absence of a catalyst
-
(Chemical Equation Presented) Fast and furious: A wide range of alcohols are acylated by acetic anhydride, in the absence of catalyst, in subcritical water in a flow-type microreaction system. The esters are selectively produced in high yields at temperatures of 200 to 250°C. Varying the amount of acetic anhydride added with respect to the alcohols allows the regioselective acylation of one or both hydroxy groups of various dihydroxy compounds (see picture).
- Sato, Masahiro,Matsushima, Keiichiro,Kawanami, Hajime,Ikuhsima, Yutaka
-
p. 6284 - 6288
(2008/04/05)
-
- PROCESS FOR THE RECTIFICATION OF MIXTURES OF HIGH-BOILING AIR-AND/OR TEMPERATURE-SENSITIVE USEFUL PRODUCTS
-
According to the invention, a process for the rectification of mixtures of high-boiling air- and/or temperature-sensitive substances which require a high separation efficiency is proposed, in particular a process for the working-up of a VE- or VEA-containing product stream. The process is characterized in particular in that, in a first purification stage, low-boiling products and unspecified isomers of the useful product are separated from the product stream virtually without loss of useful product and that, in a second purification stage, the useful product is removed in a stream having a purity of > 97% by weight and a further stream having a purity of > 92% by weight. A preferred embodiment of the process serves for working up VEA, in which the loss of useful product in the first purification stage is less than 5%, based on that amount of VEA in the feed which is added to the purification stage per unit time. Furthermore, the first purification stage may comprise a rectification column (1), from the top (la) of which the low-boiling products and the unspecified isomers of VEA are taken off, a stream containing the useful product in purified form being taken off at the side (15) and/or at the bottom (lb) of the column (1).
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-
Page/Page column 14-17
(2008/06/13)
-
- PROCESS FOR THE WORKING-UP OF A VITAMIN E- AND VITAMIN E-ACETATE-CONTAINING MIXTURE OR PRODUCT STREAM
-
The invention relates to a process for the working-up of a vitamin E (VE)- and/or vitamin E acetate (VEA)-containing product stream, which is substantially characterized by purification of a vitamin E-containing product stream, acetylation of at least a part of the purified vitamin E and purification of at least a part of the acetylated vitamin E, the purification of vitamin E and vitamin E acetate preferably being effected by distillation, for example rectification. A preferred process according to the invention is characterized in that a vitamin E-containing product stream is fed to a first rectification column (105), low-boiling products and unspecified isomers of vitamin E being taken off at the top (105a) of this first rectification column virtually without loss of useful substance, and a purified, vitamin E-containing stream being taken off at the side (105b) and/or at the bottom (105c) of the rectification column (105), at least a part of the side take-off or of the bottom take-off or at least a part of the side and bottom take-off is passed, for acetylation of vitamin E, into an acetylation stage (111), at least a part of the product stream emerging from the acetylation stage is passed into a second rectification column (115) or is taken off as useful product having a purity of ≥ 92 % by weight, and in a second rectification column, the VEA useful product is obtained as a side take-off having a purity of ≥ 97 % by weight.
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Page/Page column 21-22
(2008/06/13)
-
- MANUFACTURE OF TOCOPHEROLS USING A BISMUTH CATALYST
-
The present invention is concerned with a novel process for the manufacture of tocols and tocopherols, especially α-tocopherol, and cc-tocopheryl acetate by the reaction of a hydroquinone comprising 0 to 3 methyl groups, especially 2,3,5-trimethylhydroquinone, or 2,3,6--trimethylhydroquinone- 1 -acetate, respectively, with isophytol, phytol or a(n) (iso)phytol derivative, most preferably with isophytol, in the presence of bismuth trifluoromethanesulphonate, Bi(OS02CF3)3, as the catalyst in an organic solvent or a biphasic solvent system. A further object of the invention is the use of bismuth trifluoromethanesulphonate, Bi(OS02CF3)3, as the catalyst in Friedel-Crafts type alkylation reactions and ring-closure reactions in organic solvents.
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Page/Page column 14-15
(2008/06/13)
-
- PROCESS FOR THE MANUFACTURE OF ALKENYLATED HYDROXYLATED AROMATIC COMPOUNDS, OF CHROMAN COMPOUNDS AND OF THEIR ACYLATED DERIVATIVES
-
The present invention relates to a novel process for the manufacture of alkenylated aro-matic compounds featuring at least one hydroxy group, their ring-closure reactions to chroman derivatives, as well as the acylation of the latter and the aromatic compounds featuring at least one hydroxy group themselves. The present invention relates especially to a process for the manufacture of tocol, tocopherols and their alkanoates such as α-tocopherol (TCP) and alkanoates (TCPA) thereof, preferably α-tocopheryl acetate (TCPAc). The processes of the present invention are characterized in that at least one step of the processes is carried out in the presence of an indium salt as the catalyst. Thus, an object of the present invention is the use of an indium salt as the catalyst in Friedel-Crafts alkylation reactions of aromatic compounds featuring at least one hydroxy group and ring-closure reactions of the latter to produce chroman-ring compounds in organic solvents. According to another aspect of the invention indium salts can be used as the catalyst in processes for the manufacture of tocyl alkanoates, tocopheryl alkanoates and alkanoates of aromatic compounds featuring at least one hydroxy group by reacting tocols, tocopherol and aromatic compounds featuring at least one hydroxy group, respectively, with an acylating agent. Suitable indium salts are indium(III) salts, especially indium trichloride, indium tribromide or indium triiodide, indium(III) triflate, indium(III) bis(trifluoromethanesulfonamide) and indium(III) acetate. In preferred embodiments of the invention the processes are carried out at a pressure of at least 0.96 bar, whereby the acylation can be carried out at an absolute pressure of at least 0.02 bar.
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Page/Page column 40
(2008/06/13)
-
- PROCESS FOR THE MANUFACTURE OF TOCOPHERYL ACYLATES
-
The present invention relates to a process for the manufacture of a tocopheryl acylate which comprises reacting a tocopherol with an acylating agent in the presence of a solid basic catalyst comprising, an alkali metal and/or alkaline earth metal preferably on a solid carrier and to the use of such catalysts in the acylation of tocopherols.
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Page/Page column 11-12
(2008/06/13)
-
- PROCESS FOR THE MANUFACTURE OF α-TOCOPHERYL ACETATE
-
The present invention is concerned with a novel process for the manufacture of α-tocopheryl acetate which comprises reacting 2,3,6-trimethylhydroquinone-1-acetate with a compound selected from the group consisting of phytol (formula IV with R = OH), iso-phytol (formula III with R = OH), and (iso) phytol derivatives represented by the following formulae III and IV with R = C2-to C5-alkonoyloxy, benzoyloxy, mesyloxy, benzenesul-fonyloxy or tosyloxy, (IV) in the presence of a catalyst of the formula Mn+(R1SO3-)n, wherein Mn+ is a silver, copper, gallium, hafnium or rare earth metal cation, n is the valence of the cation Mn+, and R1 is fluorine, C1-8-perfluoroalkyl or perfluoroaryl, and, if required, cyclizing any 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate or a double bond isomer thereof obtained as an intermediate reaction product, to produce α-tocopheryl acetate. In the catalyst Mn+ is preferably Ag+, Cu+, Ga3+, Sc3+, Lu3+, Ho3+, Tm3+, Yb3+ or Hf4+.
- -
-
-
- MANUFACTURE OF TOCOPHERYL ACETATE
-
A process for the manufacture of 3-phytyl-2,5,6-trimethylhydroquinone-l-acetate, and optionally therefrom tocopheryl acetate, comprises either C-alkylating 2,3,6-trimethylhydroquinone-l-acetate with isophytol or phytol in the presence of a sulphur(VI) containing catalyst of the formulaR1SO2OH, wherein Rl signifies hydroxy, halogen, lower alkyl, halogenated lower alkyl or aryl, in an aprotic organic solvent, or O-alkylating 2,3,6-trimethylhydroquinone-l-acetate with a phytyl halide in a polar aprotic organic solvent in the presence of a base, and subjecting the so-obtained 4-O-phytyl-2,3,6-trimethylhydroquinone-l-acetate to a rearrangement reaction, and in each case optionally submitting the so-obtained 3-phytyl-2,5,6-trimethylhydroquinone-l-acetate to a ring closure reaction to produce tocopheryl acetate. The invention also includes the novel compound 3-phytyl-2,5,6-trimethylhydroquinone-l-acetate and certain stereoisomers thereof, and also the further novel compound 4-hydroxy-2,3,6-trimethyl-5-[3-(4,8,12-trimethyltridecyl)-but-3enyl]phenyl acetate which itself is one of several isomers of 3-phytyl-2,5,6- trimethylhydroquinone-l-acetate formed by isomerization under the influence of heating, e.g. during its distillation as part of the isolation and purification procedure following its manufacture as indicated above. (All-rac)-α -tocopherol, which may be derived from its acetate, is known to be the most active industrially important member of the vitamin E group.
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-
-
- Method for continuously acylating chromanol ester derivatives
-
A process is described for continuously preparing chromanol ester derivatives, in particular for continuously preparing carboxylic esters of tocopherols and tocotrienols by continuous acylation with carboxylic acids or carboxylic anhydrides.
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-
-
- Method for preparing vitamin e
-
The invention concerns a novel method for preparing vitamin E. More particularly, it concerns a novel method for the condensation of Arimethylhydroquinone and isophytol.
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-
-
- Intermediates for use in the preparation of vitamin E
-
Novel intermediate compounds which can be used in the preparation of phytone and Vitamin E and a process for the preparation thereof. A process for the preparation of phytone and Vitamin E from these compounds is also claimed.
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-
-
- Process for the preparation of tocol acylates and tocopherol acylates
-
The present invention relates to a process for preparing tocol acylate or tocopherol acylate having the following steps: a) combining tocol or tocopherol with an acylating agent to form a reaction mixture; b) irradiating the reaction mixture with microwave energy to from tocol acylate or tocopherol acylate; and c) isolating the tocol acylate or tocopherol acylate from the reaction mixture.
- -
-
-
- Process for the production of alpha -tocopherol esters
-
A process for the production of alpha -tocopherol esters, derivatives or homologs thereof of the general formula in which the mono- or diester of a hydroquinone is reacted with an allyl alcohol derivative or an allyl alcohol in the presence of zinc halides and proton-liberating acids at a temperature of 25 DEG to 100 DEG C.
- -
-
-
- Rhodium(I)-catalyzed addition of phenols to dienes. A new convergent synthesis of vitamin E
-
A highly convergent and atom-economical synthesis of (dl)-[α]- tocopherol (vitamin E) is proposed, the realization of which was made possible by the discovery of the regioselective Rh(I)-catalyzed arylation of β-springene with trimethylhydroquinone. Other phenolic compounds and 2- substituted-1,3-dienes were shown to undergo this transformation. (C) 2000 Elsevier Science Ltd.
- Bienaymé, Hugues,Ancel, Jean-Erick,Meilland, Pierre,Simonato, Jean-Pierre
-
p. 3339 - 3343
(2007/10/03)
-
- Process for producing chromans
-
A process for producing chromans, comprising reacting a phenol, a formaldehyde and an alcohol in the presence of a secondary amine and an acid, to generate an alkoxymethylphenol compound with the ortho position to the phenolic hydroxyl group substituted with an alkoxymethyl group, and reacting the alkoxymethylphenol compound with an unsaturated compound having a carbon--carbon double bond.
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-
-
- Nanoparticles coated with a lamellar phase based on silicone surfactant and compositions containing them
-
The present invention relates to nanoparticles, and in particular nanocapsules, provided with a lamellar coating obtained from a silicone surfactant, and to their use in a composition, in particular a topical composition, for treatment of the skin, mucosae, nails, scalp and/or hair.
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-
-
- Preparation of α-tocopherol or α-tocopheryl acetate by reacting trimethylhydroquinone and phytol or isophytol, with recycling of the zinc halide condensation catalyst
-
A process for preparing α-tocopherol or α-tocopheryl acetate by reacting 2,3,5-trimethylhydroquinone with isophytol or phytol in the presence of a zinc halide condensation catalyst and a proton donor in a solvent with or without subsequent esterification with acetic anhydride, which comprises A. carrying out the reaction in a nonpolar solvent which is only slightly water-miscible, if at all and B. introducing the required zinc halide into the reaction in the form of a mixture of from 1 to 4 mol of water per mol of zinc halide. The possibility of introducing the zinc halide required in the process according to the invention in the form of a mixture of zinc halide and water which can be readily handled and metered at from 50 to 200° C. without impairing the yield and purity of the tocopherol opens the way to an advantageous recycling of the zinc halide after the reaction by separating off or extracting and recycling the zinc halide in the form of a from 60 to 90% strength by weight solution or pumpable magma.
- -
-
-
- Process for producing DL-tocopherols and intermediates therefor
-
The present invention relates to a process for producing dl-tocopherols and intermediates for the production. dl-Tocopherols obtained by the present invention are useful compounds that are used as food additives, feed and medicaments.
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-
-
- Preparation of vitamin E
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A process for preparing dl-α-tocopherol or dl-α-tocopheryl acetate by acid-catalyzed reaction of 2,3,5-trimethylhydroquinone (TMH) with phytol or isophytol in a solvent at elevated temperature, with or without subsequent esterification of the resulting tocopherol with acetic anhydride, entails the reaction being carried out in the presence of a mixture of ortho-boric acid and certain aliphatic di- or tricarboxylic acids, preferably in the presence of a mixture of ortho-boric acid and oxalic acid.
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- Tocopherol derivatives useful in the synthesis of vitamin E and their preparation
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Tocopherol derivatives of the formula: STR1 in which X and X1, which may be identical or different, each represent hydrogen or chlorine and their acetates are useful in the synthesis of vitamin E.
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- Intermediate phenolic compounds for the catalytic synthesis of chromans
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A catalytic synthesis of chromans in racemic or optically active forms, including intermediates thereto; the synthesis employs an asymmetric palladium (II) catalyzed oxidative cyclization of a 2-homoallylphenol and provides intermediates useful in making chromans, especially vitamin E in racemic or optically active forms.
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- Process for separation of tocopherol homologues
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A process for separating the various members of a tocopherol homologue mixture to obtain fractions of the separate tocopherol homologues. The isolation of the various tocopherol homologues is accomplished by selective deacylation of tocopheryl esters followed by separation of the esters from the free tocopherols.
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- Manufacture of tocopherol
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In the manufacture of tocopherol (vitamin E) by reaction of isophytol with trimethylhydroquinone in the presence of zinc chloride and acid in a hydrocarbon solvent one of the starting compounds, isophytol, is pretreated with small amounts of ammonia or an amine. Tocopherol is obtained in higher yield and purity.
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- Process for the preparation of Dl-α-tocopherol of high purity
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A process for preparing high purity dl-α-tocopherol by condensing trimethylhydroquinone and a phytol in the presence of zinc chloride, a mineral acid and, either silica-alumina or silica gel, or a combination of silica-alumina and silica gel, is described.
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- Antioxidant chroman compounds
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The (6-hydroxy-chroman-2-yl) acetic or carboxylic acid derivatives useful as antioxidants and a method for preparing these derivatives from hydroquinones and intermediates in this synthesis as well as the use of these derivatives as intermediates in the preparation of optically active alpha-tocopherol.
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