- Synthesis method of m-methoxybenzyl alcohol
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The invention discloses a synthesis method of m-methoxybenzyl alcohol. The synthesis method comprises the steps: (1) by taking ethylene glycol and m-chlorobenzaldehyde as raw materials and sulfuric acid as a catalyst, carrying out condensation reaction in a solvent to prepare ethylene glycol condensed m-chlorobenzaldehyde; (3) dissolving the ethylene glycol condensed m-chlorobenzaldehyde in an organic solvent to obtain a mixed solution; (4) adding a condensing agent into the mixed solution under a stirring condition, and heating for reaction to form a reaction system containing ethylene glycol condensed m-methoxybenzaldehyde; (5) evaporating to remove the organic solvent in the reaction system, then cooling, adjusting the pH value of the system, and carrying out phase splitting on the reaction system after the pH value is adjusted to obtain an organic phase I; (6) adding a catalyst and a metal reducing agent into the organic phase I, resolving acetal and reducing to obtain a reaction solution containing a crude product of m-methoxybenzyl alcohol; and (7) continuing to split phases of the reaction liquid to obtain an organic phase II, and washing, drying and rectifying the organic phase II to obtain refined m-methoxybenzyl alcohol.
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Paragraph 0027; 0031-0033; 0041; 0042; 0046-0048; 0055; ...
(2021/06/26)
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- Inhibition by Water during Heterogeneous Br?nsted Acid Catalysis by Three-Dimensional Crystalline Organic Salts
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A new self-assembled and self-healing class of metal free, recyclable, heterogeneous Br?nsted acid catalysts has been developed by the protonation of aniline derivatives (tetrakis(4-aminophenyl)methane, leuco-crystal violet, benzidine, and p-phenylenediamine) with aromatic sulfonic acids (tetrakis(phenyl-4-sulfonic acid)methane, and 2,6-naphthalenedisulfonic acid). As a result, five three-dimensional crystalline organic salts (F-1a, F-1b, F-1c, F-2, and F-3) were obtained, linked by hydrogen bonds and additionally stabilized by the opposite charges of the components. Frameworks F-2 and F-3 were prepared for the first time and characterized by elemental analysis, X-ray structural analysis (for F-2), thermogravimetry, SEM, and FTIR spectroscopy. The catalytic activities of crystalline organic salts F-1-3 have been explored in industrially important epoxide ring-opening and acetal formation reactions. The presence of encapsulated water inside frameworks F-1a and F-2 had an inhibitory effect on the performance of the catalysts. X-ray diffraction analysis of hydrated and dehydrated samples of F-1a and F-2 indicated that water of crystallization served as a cross-linking agent, diminishing the substrate induced "breathing"affinities of the frameworks.
- Belokon, Yuri N.,Gak, Alexander,Khakina, Ekaterina,Khrustalev, Victor N.,Korlyukov, Alexander A.,Kuznetsova, Svetlana,Li, Han,Lobanov, Nikolai,Nelyubina, Yulia,North, Michael,Peregudov, Alexander S.,Riazanov, Vladimir,Zhereb, Vladimir
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p. 6364 - 6372
(2021/10/20)
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- Palladium on Carbon-Catalyzed Chemoselective Oxygen Oxidation of Aromatic Acetals
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The development of an unprecedented chemoselective transformation has contributed to forming a novel synthetic process for target molecules. Chemoselective oxidation of aromatic acetals has been accomplished using a reusable palladium on carbon catalyst under atmospheric oxygen conditions to form ester derivatives with tolerance of aliphatic acetals and ketals.
- Yasukawa, Naoki,Asai, Shota,Kato, Maho,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
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supporting information
p. 5604 - 5607
(2016/11/17)
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- Acetalization of carbonyl compounds catalyzed by bismuth triflate under solvent-free conditions
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Carbonyl compounds were converted to the corresponding 1,3-dioxolanes and 1,3-dioxanes with ethylene glycol and 1,3-propandiol in the presence of bismuth triflate under solvent-free conditions. In addition, high chemoselective protection of aldehydes in the presence of ketones has been achieved.
- Aliyan, Hamid,Fazaeli, Razieh,Massah, Ahmad Reza,Momeni, Ahmad Reza,Naghash, Hamid Javaherian,Moeinifard, Behzad
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experimental part
p. 873 - 876
(2012/04/05)
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- Highly efficient and chemoselective acetalization of carbonyl compounds catalyzed by new and reusab e zirconyl triflate, zr0(0tf)2
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Various types of aromatic aldehydes were efficiently converted to their corresponding 1,3-dioxanes and 1,3-dioxolane with 1,3-propanediol and ethylene glycol, respectively, in the presence of catalytic amount of ZrO(OTf) 2 in acetonitrile at room temperature. The catalyst can be reused several times without loss of its catalytic activity. Very short reaction times, selective acetalization of aromatic aldehydes in the presence of aliphatic aldehydes and ketones, very mild reaction conditions, reusability of the catalyst, and easy workup are noteworthy advantages of this method.
- Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Tangestaninejad, Shahram,Mirkhani, Valiollah,Yazdani, Parvin,Ghorjipoor, Saeedeh
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experimental part
p. 131 - 135
(2009/09/30)
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- Intermolecular reactions of chlorohydrine anions: Acetalization of carbonyl compounds under basic conditions
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Nonenolizable aldehydes and ketones react with 2-chloroethanol and 3-chloropropanol under basic conditions (t-BuOK, DMF/THF) with formation of 2-substituted 1,3-dioxolanes and 1,3-dioxanes, respectively. Conversion of the two-step addition-alkylation process depends on the electrophilicity of the carbonyl group that governs the equilibrium of addition of chloroalkoxides. This method of protection of carbonyl groups in the form of cyclic acetals under kinetically controlled conditions is complementary to the acid-catalyzed reaction with diols.
- Barbasiewicz, Michal,Makosza, Mieczyslaw
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p. 3745 - 3748
(2007/10/03)
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- 2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO) as a versatile, efficient, and chemoselective catalyst for the acetalization and transacetalization of carbonyl compounds, the preparation of acetonides from epoxides and acylals (1,1-diacetates) from aldehydes
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The efficient and chemoselective preparation of acetals and ketals from carbonyl compounds, transacetalization reactions, the conversion of epoxides to acetonides, and the preparation of acylals from aldehydes in the presence of catalytic amounts of 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TABCO) are described.
- Firouzabadi, Habib,Iranpoor, Nasser,Shaterian, Hamid Reza
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p. 2195 - 2205
(2007/10/03)
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- Supported catalysts in alkoxylation of substituted aromatics.
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The nucleophilc substitution of aromatics by sodium methylate and phenate has been studied using (3-bromophenyl)dioxolane and copper chloride supported catalysts.The aim of this study was the preparation of re-usable catalysts whose easy separation from the organic medium would permit a continual operation with better yields than batch operations using bulk catalysts.Purification losses and waste rejections are also lowered by the use of supported catalysts.Various alumina, silica, and "Chromosorb" supports were chosen according to their mechanical strength, specific surface area, and particle size.In the case of alumina, only very low activities were observed for all specific surface areas.The formation of by-products, and the hydrolysis of the dioxolane ring in the reagent or the product, show the specific action of these supports due to their acidic sites.The low activity can be attributed to both poor fixation of the active phase on the carrier and a support effect on the intermediate.The silica carriers give active catalysts which have a delayed reaction.A reaction between sodium methylate and silica was observed, which explains both the partial conversion of the reagent and the time delay.Moreover, the kinetic rate seems to be lower than for bulk catalysts, and the conversion-time curves are interpreted by temperature evolution during reaction.Catalysts prepared with "Chromosorb" carriers present good activity and selectivity.The support is not destroyed by sodium methylate and no loss of active phase is observed when it is re-used.These catalysts have better activity (relative to the active mass) and yield than bulk cuprous chloride.They were used in several runs without any decrease in activity or selectivity.A transient product retention was observed, but the mass balance was recovered on the second run.The best support for the catalyst of the reaction is "Chromosorb PNAW".The catalyst is then also active and selective for 3-phenoxybenzaldehyde synthesis.Complete conversion is obtained in a shorter time by the progressive introduction of both reagents into the reactor containing catalyst, than by the addition of sodium methylate to the resident halide.The reaction could then be carried out in a continuous flow reactor.The supprot for copper chloride in these nucleophilic substitutions must be neutral because the donor-acceptor properties of the support could change electron density in the intermediate complex.In the case of acceptor (acidic) effect, a strong aromatic-metal interaction would produce a stable intermediate, whereas the donor (basic) effect would not permit the electron transfer from the aromatic system to the metal required for nucleophilic attack; both effects lead to poor activities.Acidic supports also give rise to isomerization and hydrolysis side-reactions, which are not observed with bulk catalyst.The charactertistic of "Chromosorb" avoid such effects, and the specific surface area is sufficient ...
- Bebon-Rampal, C.,Vanhove, D.
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p. 501 - 508
(2007/10/02)
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