- 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 0041-0044
(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 0063-0066
(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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- 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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- 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 0063; 0064; 0065; 0066; 0067; 0068; 0069
(2019/10/02)
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- Synthesis of Nipagin esters using acidic functional ionic liquids as catalysts
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(Chemical Equation Presented) Several Bronsted acidic functional ionic liquids (FILs) with an alkane sulfonic acid group were synthesized. These FILs as dual solvent-catalysts for Nipagin esterification reactions were investigated. The results indicated that [HSO3-pMIM]HSO4 has the best catalytic activity and recyclability among the various kinds of FILs investigated, and its structure was characterized by infrared and NMR. The [HSO3-pMIM]HSO4 could be easily separated from the reaction mixture and reused without noticeably decreasing the catalytic activity. Copyright Taylor & Francis Group, LLC.
- Wang, Guohua,Li, Lu,Xie, Congxia,Yu, Shitao,Liu, Fusheng,Ye, Xiaoling
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experimental part
p. 945 - 952
(2011/04/25)
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- Non-antibiotic antibacterial activity of dodecyl gallate
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Dodecyl (C12) gallate (3,4,5-trihydroxybenzoate) (1) was found to possess antibacterial activity specifically against Gram-positive bacteria, in addition to its potent antioxidant activity. The time-kill curve study indicates that this amphipathic gallate exhibits bactericidal activity against methicillin resistant Staphylococcus aureus (MRSA) strains. Dodecyl (lauryl) gallate inhibited oxygen consumption in whole cells and oxidation of NADH in membrane preparation. The antibacterial activity of this gallate comes in part from its ability to inhibit the membrane respiratory chain. As far as alkyl gallates are concerned, their antimicrobial spectra and potency depend in part on the hydrophobic portion of the molecule.
- Kubo, Isao,Fujita, Ken-ichi,Nihei, Ken-ichi,Masuoka, Noriyoshi
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p. 573 - 580
(2007/10/03)
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- Optically active compound having XI-valerolactone ring and liquid crystal composition comprising same
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An optically active compound having a δ-valerolactone ring which is a ferroelectric liquid crystal and is represented by the following general formula (I): STR1 wherein m is an integer of from 1 to 8, Z is a group represented by the following formula: STR2 in which each of l and k is a number of 1 or 2 and l and k satisfy the requirement of 2≤(l+k)≤3, X stands for a direct bond, STR3 Y stands for STR4 and A1 and A2 independently stand for --H, --F or --Cl, STR5 R stands for STR6 in which n is an integer of from 1 to 18, and * indicates the asymmetric carbon atom.
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- New Liquid Crystal Compounds: (+)-4-Alkoxycarbonylphenyl-4-benzoate
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New Liquid Crystal Compounds: (+)-4-Alkoxycarbonylphenyl-4-benzoates (5) were synthesized.The mesomorphic behavior of these compounds is compared with that of (+)-4-(2-methylbutyloxycarbonyl)phenyl 4-(5-alkyl-1,3-dioxan-2-yl)benzoates (6).Compounds 5 exhibited cholesteric and smectic A phases and their transition temperatures to the isotropic state were lower than those of corresponding compounds 6.These properties are supposed to originate in the greater molecular widths of the formers caused by 2-methylbutyl group at the 5 position of the 1,3-dioxane ring.Though compounds 6 exhibit the ferroelectric behavior, compounds 5 don't.This might mean that a short distance between the carbonyl and chiral group is one factor for the appearance of the SmC* phase.
- Haramoto, Y.,Kamogawa, H.
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p. 161 - 166
(2007/10/02)
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