- Method for preparing paraben
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The invention discloses a method for preparing paraben. The method comprises the following steps: adding p-hydroxybenzoic acid (Amol), an alcohol (Bmol) and a benzimidazole ionic liquid (Cmol) into adry three-neck flask, slowly heating, carrying out reflux reaction, and carrying out TLC monitoring until reaction is finished; carrying out reduced pressure distillation to remove a solvent, washingresidues with ethyl acetate, carrying out suction filtration, and carrying out spin-drying on an obtained filtrate to obtain paraben. The yield can reach 90% or above; an obtained filter cake is the benzimidazole ionic liquid and can be recycled; the ratio of A to B to C is 1: 5: (0.2-0.5). The method provided by the invention has the advantages that the catalyst can be recycled, green and environment-friendly effects are realized, the cost is reduced, and the method is an efficient method for synthesizing paraben.
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Paragraph 0033-0036
(2020/03/25)
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- Proline ionic liquid and method for catalyzing synthesis of paraben by proline ionic liquid
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The invention discloses proline ionic liquid and a method for catalyzing synthesis of paraben by the proline ionic liquid. The preparation method comprises the following steps: adding N-butylbenzimidazole, a solvent and proline into a dry three-neck flask, carrying out reflux reaction until the reaction is complete (monitored by TLC), evaporating to remove the solvent to obtain a faint yellow oilyliquid, namely the proline ionic liquid, adding p-hydroxybenzoic acid, alcohol and a proline ionic liquid into a dry three-necked bottle, heating to reflux reaction, monitoring by TLC until the reaction is finished, evaporating under reduced pressure to remove the solvent, extracting residues with diethyl ether, evaporating the diethyl ether phase to remove the solvent to obtain the methylparabenwith the yield of 88% or above, wherein the remainder is the ionic liquid, and carrying out washing and drying so that the product can be recycled for many times. The method disclosed by the invention is efficient, environment-friendly and safe, the catalyst can be recycled, the cost is reduced, the requirement on equipment is low, and the method is an efficient method for synthesizing paraben.
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Paragraph 0055-0058
(2020/09/16)
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- Novel Benzothiazole Ionic Liquids as Catalysts for the Synthesis of Parabens
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Abstract: A simple and green approach to the esterification of p-hydroxybenzoic acid and aliphatic alcohols to obtain parabens was developed. First, two novel benzothiazole ionic liquids [HBth]H2PW12O40 (IL1) and [HBth]H4PMo12O41 (IL2) were synthesized with benzothiazole and heteropolyacids as starting materials. The synthesized ionic liquids were characterized by FTIR spectroscopy, TGA, PXRD analysis, and SEM. The application of IL1 and IL2 as catalysts for the synthesis of parabens was explored. The results showed that the ILs had a high catalytic activity in the synthesis of parabens, and, at the same time, they could be easily recovered and reused five times without loss of activity.
- Liu, B.,Liu, Y.,Sun, J.,Yin, D.
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p. 1476 - 1483
(2020/10/02)
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- A process for preparing Nepal jin zhi method (by machine translation)
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The invention discloses a method for preparing Nepal jin zhi method: in a reaction container by adding of formula choline chloride (Amol) and methanesulfonic acid (Bmol), for 80 °C stirring to complete dissolution shall be low altogether [...]; cooling to room temperature, then added to the hydroxy benzoic acid of formula (Cmol) acrylic (Dmol), slow heating, reflux reaction, TLC monitoring until a reaction is finished (1 - 2 h); reaction liquid-cooled to the room temperature, precipitate solid, filtered, cake of a small amount of washing, get [...], a yield of 90% or more; recycling the filtrate to obtain low altogether [...]. Wherein A: B: C: D is 1: (1 - 4): 1: (1.1 - 1.5). The method of the invention short reaction time, efficiency is high, the catalyst can be recycled, environmental protection, and reducing the cost; to reduce the consumption of the stinging; low requirements on equipment, is an efficient method of synthesizing [...]. (by machine translation)
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Paragraph 0049; 0050; 0051; 0052; 0053; 0054; 0055
(2019/10/02)
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- Single-Step Dual Functionalization: One-Pot Bromination-Cross-Dehydrogenative Esterification of Hydroxy Benzaldehydes with CCl 3 Br - A Comparison with Selectfluor
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Bromination of phenolic compounds without directly using molecular bromine possesses much importance. In this article an Ir III /CCl 3 Br-assisted single-step double functionalization of hydroxy benzaldehydes is reported. It involves simultaneous esterification of the aldehyde group and bromination of the aryl ring of phenolic aldehydes in one-pot. The reaction proceeds under mild conditions in the presence of 445 nm blue LED light to obtain highly functionalized bromo hydroxy benzoates in moderate to good yields. In comparison, Selectfluor as an oxidant gives only non-bromo phenolic esters.
- Talukdar, Ranadeep
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supporting information
p. 1713 - 1718
(2019/08/28)
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- Method for preparing parabens
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The invention discloses a method for preparing parabens. The method comprises the following steps: adding an appropriate amount of methanol (A) into a reaction container, sequentially adding a benzothiazole ionic liquid (B) and p-hydroxybenzoic acid (C) while stirring, slowly heating the obtained solution to a reflux temperature, and carrying out TLC monitoring until the reaction ends; and distilling off methanol, washing the obtained reaction product with ethyl acetate, carrying out suction filtration (the filter cake is the benzothiazole ionic liquid), carrying out rotary evaporation on thefiltrate, washing the product with water, carrying out suction filtration, and drying the product to obtain colorless crystals (methylparaben) at a yield of 91% or above. A ratio of A:B:C is 1:4:0.15, and a catalyst has a high activity and a good stability, and can be recycled. Additionally, the method also has a high esterification rate of 87%% or above to other parabens (ethylparaben, propylparaben, isopropylparaben, butylparaben and n-dodecyl 4-hydroxybenzoate), and provides a good method for industrial synthesis of parabens.
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Paragraph 0026; 0030-0032; 0048; 0050-0053
(2019/07/01)
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- Palladium-Catalyzed Aerobic Oxidative Carbonylation of C–H Bonds in Phenols for the Synthesis of p-Hydroxybenzoates
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This work reports the synthesis of p-hydroxybenzoates directly from phenols by oxidative carbonylation of phenolic C–H bonds, proceding through oxidative iodination. The developed methodology is efficient and economically attractive because phenols are cheap and easily available starting materials. This one-pot strategy was expediently applied to the synthesis of a variety of p-hydroxybenzoates by utilizing simple primary and secondary alcohols with different phenols under mild reaction conditions. Advantageously, the procedure has no need for co-catalysts, co-solvents or external ligands. The utilization of molecular oxygen as a terminal oxidant for C–H bond oxidation represents an additional benefit.
- Gaikwad, Vinayak V.,Bhanage, Bhalchandra M.
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p. 2877 - 2881
(2018/06/21)
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- Mono-/dihydroxybenzoic acid esters and phenol pyridinium derivatives as inhibitors of the mammalian carbonic anhydrase isoforms I, II, VII, IX, XII and XIV
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Using hydroxy-/dihydroxybenzoic acids as leads, a series of methyl, ethyl and iso-propyl esters of 4-hydroxy-benzoic acid, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-dihydroxybenzoic acids and of coumaric acid, were obtained and investigated for the inhibition of six mammalian carbonic anhydrase (CA, EC 4.2.1.1) isoforms, that is, the cytosolic CA I, II and VII, and the transmembrane CA IX, XII and XIV, many of which are established drug targets. Other compounds incorporating phenol/catechol moieties were obtained from dopamine by reaction with fluorescein isothiocyanate or with 2,4,6-trisubstituted pyrylium salts. Some aminophenols were also derivatized in a similar manner, by using pyrylium salts. Many of these compounds showed increased inhibitory action compared to the lead compounds from which they were obtained, with efficacy in the submicromolar range against most investigated CA isoforms. As phenols are a class of less investigated CA inhibitors (CAIs) compared to the sulfonamides, and their mechanism of inhibition is less well understood, compounds of the type designed here may be helpful in gaining more insights into these phenomena.
- Carta, Fabrizio,Vullo, Daniela,Maresca, Alfonso,Scozzafava, Andrea,Supuran, Claudiu T.
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supporting information
p. 1564 - 1569
(2013/04/10)
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- Catalytic asymmetric synthesis of a tertiary benzylic carbon center via phenol-directed alkene hydrogenation
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An expeditious synthetic approach to chiral phenol 1, a key building block in the preparation of a series of drug candidates, is reported. The strategy includes a cost-effective and readily scalable route to cyclopentanone 3 from isobutyronitrile (10). The sterically hindered and enolizable ketone 3 was subsequently employed in a challenging Grignard addition mediated by LaCl 3?2LiCl. A novel preparation of the lanthanide reagent required for this transformation is described. To complete the process, a highly enantioselective hydrogenation step afforded the target (1). The importance of the phenol group to the success of this asymmetric transformation is discussed.
- Caille, Seb,Crockett, Rich,Ranganathan, Krishnakumar,Wang, Xiang,Woo, Jacqueline C. S.,Walker, Shawn D.
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scheme or table
p. 5198 - 5206
(2011/08/09)
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- Quantitative structure-activity relationships of pine weevil antifeedants, a multivariate approach
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Antifeedant activity of mainly phenylpropanoic, cinnamic, and benzoic acids esters was tested on the pine weevil, Hylobius abietis (L.). Of 105 compounds screened for activity, 9 phenylpropanoates, 3 cinnamates, and 4 benzoates were found to be highly active antifeedants. To understand the structure-activity relationships of these compounds, a multivariate analysis study was performed. A number of molecular and substituent descriptors were calculated and correlated to results from two-choice feeding tests with H. abietis. Three local models were developed that had good internal predictive ability. External test sets showed moderate predictivity. In general, low polarity, small size, and high lipophilicity were characteristics for compounds having good antifeedant activity.
- Sunnerheim, Kerstin,Nordqvist, Anneli,Nordlander, Goeran,Borg-Karlson, Anna-Karin,Unelius, C. Rickard,Bohman, Bjoern,Nordenhem, Henrik,Hellqvist, Claes,Karlen, Anders
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p. 9365 - 9372
(2008/03/17)
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- Na2CO3/SOCl2: A mild and convenient reagent for the preparation of isopropyl carboxylates
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Na2CO3/SOCl2 has been used for esterification of aliphatic and aromatic acids with isopropanol. This esterification method is compatible with a wide assortment of functional groups.
- Kazemi, Foad,Kiasat, Ali Reza,Mombaini, Began
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p. 1187 - 1191
(2007/10/03)
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- Thermosensitive recording material and color developer compound therefor
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A thermosensitive recording material has a support and a thermosensitive coloring layer formed thereon containing a leuco dye and a color developer capable of inducing color formation in the leuco dye upon application of heat thereto, with the color developer including at least one compound (A) having in a molecule thereof at least two aromatic ring moieties with specific structures, selected from the group consisting of an aromatic ring moiety having at least one carboxyl group and electron-attracting functional group, an aromatic ring moiety having at least one carboxyl group and electron-donating functional group, and an aromatic ring moiety having at least one carboxyl group, free of the electron-attracting and electron-donating functional groups. An aromatic carboxylic acid compound serving as the above-mentioned compound (A) and the producing method thereof are also disclosed.
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- Silica Chloride: A Versatile Heterogeneous Catalyst for Esterification and Transesterification
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Silica chloride has been found to be an efficient catalyst for esterification of carboxylic acids (aliphatic, aromatic and conjugated) with alcohols (primary, secondary and tertiary) as well as for transesterification of esters (by both alcoholysis and acidolysis).
- Srinivas,Mahender,Das, Biswanath
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p. 2479 - 2482
(2007/10/03)
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- Phenolic compounds
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A phenolic compound having formula (I): STR1 wherein X represents a chlorine atom or a methyl group, and a recording material comprising a coloress or light-colored leuco dye and the above phenolic compound serving as a color developer for the leuco dye are disclosed.
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- Ester Derivatives of 2,6-Bis(1-pyrrolidinylmethyl)-4-benzamidophenol as Short-Acting Antiarrhythmic Agents. 1
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In an effort to find a replacement for the iv antiarrhythmic drug lidocaine having reduced systemic and central nervous system effects, activity against supraventricular as well as ventricular arrhythmias, and a biological half-life of less than 15 min, derivatives of the orally active class Ic clinical agent 2,6-bis(1-pyrrolidinylmethyl)-4-benzamidophenol, 1 (ACC-9358), were synthesized and tested.Compounds with ester groups attached to the phenyl ring were either weakly active or toxic.Replacement of the formanilide function with alkyl esters afforded compounds with antiarrhythmic activity in the range of 1.When the ester carboxyl was separated from the bis(aminomethyl)phenol by methylene units, very short half-lives were observed in human blood.In general, these compounds also had low lipophilic character.
- Stout, David M.,Black, Lawrence A.,Barcelon-Yang, Cynthia,Matier, W. L.,Brown, Barry S.,et al.
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p. 1910 - 1913
(2007/10/02)
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