93-28-7Relevant academic research and scientific papers
Continuous ion-exchange resin catalysed esterification of eugenol for the optimized production of eugenyl acetate using a packed bed microreactor
Lerin,Catani,Oliveira,Massi,Bortolini,Cavazzini,Giovannini
, p. 76898 - 76903 (2015)
A green scalable flow-synthesis process for the production of eugenyl acetate, an eugenol derivative with potential applications in food and medicinal chemistry, was developed. Through batch experiments, the anion-exchange resin Amberlyst A-21 was recognized as a suitable catalyst for the esterification of eugenol with acetic anhydride. Next, the process was switched from batch- to flow-mode by using a packed-bed microreactor integrated in an instrumental platform that permitted at the same time continuous control of the main process parameters (flow rate, feed mixture composition, temperature) and the on-line HPLC analysis of the reactor effluent. Thanks to this apparatus, a number of experiments with different reaction conditions have been easily performed to evaluate the effects of temperature and reagent molar ratios on eugenyl acetate production. The results have been used to carry out a central composite rotatable experimental design (CCRD) whose derived response surface model (RSM) suggested an optimal temperature and acetic anhydride to eugenol molar ratio of 95 °C and 3:1, respectively. The goodness of these theoretically deduced parameters has been experimentally confirmed obtaining, with a flow rate of 40 μL min-1, a 95% conversion. The Amberlyst A-21 packed-bed microreactor also demonstrated good long-term stability ensuring, under the above optimized conditions, a high and stable conversion (over 93%) for prolonged reaction times.
Synthesis of 5-Hydroxy-4-methoxy-α-methyl-(1,2-benzobutane sultone) from eugenol and eugenil acetate
Sudarma,Supiani,Syafitri,Hidayati,Oltantia,Darmayanti
, p. 2411 - 2414 (2018)
The purpose of this study was to develop an efficient synthesis route to pharmacologically interesting sultone derivatives from readily accessed natural products. Synthetic approach of 5-hydroxy-4-methoxy-α-methyl-(1,2-benzobutane sultone) via eugenol (1) produced only in moderate yield (64 %). On the other hand synthetic approach via eugenil acetate (2) gave 5-hydroxy-4-methoxy-α-methyl-(1,2-benzobutane sultone) in high yield (96 %). Eugenol approach involved only one step reaction due to direct reaction of eugenol with chlorosulfonic acid but in eugenil acetate approach involved two-step reactions due to its preparation of eugenol before reaction with chlorosulfonic acid. Eugenil acetate was prepared smoothly in good yield by esterification of phenolic group of eugenol with acetic anhydride in the presence of sodium bicarbonate. A variety of bicarbonate catalysts such as NaHCO3, Na2CO3 and K2CO3 were investigated in O-acetylation of eugenol to afford eugenil acetate (84 %), (72 %) and (88 %), respectively. Structures of all the products have been established by spectral and GC-MS analysis data.
Synthesis of eugenyl acetate by enzymatic reactions in supercritical carbon dioxide
dos Santos, Philipe,Zabot, Giovani L.,Meireles, M. Angela A.,Mazutti, Marcio A.,Martínez, Julian
, p. 1 - 9 (2016)
Supercritical carbon dioxide (SC-CO2) as reaction medium has gained attention in the production of terpenic esters catalyzed by lipases. Therefore, this work investigated the production of eugenyl acetate by esterification of eugenol and acetic anhydride in SC-CO2 using two commercial lipases (Lipozyme 435 and Novozym 435) as catalysts. The influence of enzyme concentration (1–10% weight/weight), substrates’ molar ratio (1:1 to 5:1), temperature (40–60?°C) and pressure of SC-CO2 (10–30?MPa) on the esterification rate (X; %) and specific productivity (SP; kg of product/kg of catalyst x hour) were evaluated. A home-made high-pressure stirred-batch reactor (100?ml) was used in the experiments. The use of Novozym 435 achieved higher conversion and specific productivity of eugenyl acetate than Lipozyme 435. An excess of acetic anhydride (5:1?M/M) and high enzyme concentration (10%) achieved higher esterification rates than the lowest conditions (1% and 1:1?M/M). The optimal temperatures and pressure for the synthesis of eugenyl acetate in SC-CO2 were 50 and 60?°C at 10?MPa, respectively. The phase behavior of the reaction system and the synthesis in organic medium were also studied. Kinetic experiments performed at 40, 50 and 60?°C indicated that the reaction follows the simple Ping-Pong Bi-Bi mechanism and the affinity of acetic anhydride to enzyme was larger than that of eugenol.
One-pot hydroformylation/O-acylation of propenylbenzenes for the synthesis of polyfunctionalized fragrances
Delolo, Fábio G.,Vieira, Gabriel M.,Villarreal, Jesus A.A.,dos Santos, Eduardo N.,Gusevskaya, Elena V.
, p. 272 - 279 (2020/06/17)
A process involving the hydroformylation/O-acylation of propenylbenzenes with a phenolic group is described for eugenol, isoeugenol, chavicol, propenyl guaethol, 2-allylphenol, and 2-allyl-6-methylphenol. The reactions occur in parallel, under the same reaction conditions in anisole, a solvent with an impressive sustainability rank comparable to those of ethanol and water. The products contain formyl and acetoxy moieties, both established olfactory groups in flavor and fragrance industry, and present potential as new fragrance components with less allergenic properties. To the best of our knowledge, this is the first time that a one-pot process involving hydroformylation combined with further functionalization in a remote site is described.
Biotechnological Potential of Eugenol and Thymol Derivatives Against Staphylococcus aureus from Bovine Mastitis
Nunes, Daiana O. S.,Vinturelle, Rafaelle,Martins, Francislene J.,dos Santos, Thiago F.,Valverde, Alessandra Leda,Ribeiro, Carlos Magno R.,Castro, Helena C.,Folly, Evelize
, p. 1846 - 1855 (2021/04/29)
Bovine mastitis is an infectious disease that affects the mammary gland of dairy cattle with considerable economic losses. Staphylococcus aureus is the main microorganism involved in this highly contagious process, and the treatment is only using antibiotics. Currently, the search for new treatment and/or compounds is still in need due to microbial resistance. In this work, we evaluated the potential of eugenol and thymol derivatives against S. aureus strains from bovine mastitis. On that purpose, nine derivatives were synthesized from eugenol and thymol (1–9), and tested against 15 strains of S. aureus from subclinical bovine mastitis. Initially, the strains were evaluated for the biofilm production profile, and those with strong adherence were selected to the antimicrobial sensitivity determination in the Minimum Inhibitory Concentration (MIC) assays. Herein the compounds toxicity was also evaluated by in silico analysis using Osiris DataWarrior software. The results showed that 60% of the strains were considered strongly adherent and three strains (S. aureus 4271, 4745 and 4746) were selected for the MIC tests. Among the nine eugenol and thymol derivatives tested, four were active against the evaluated strains (MIC = 32?μg?mL?1) within CLSI standard values. In silico analysis showed that all derivatives had cLopP ??4 and TPSA 140 ?2, and similar theoretical toxicity parameters to some antibiotics currently on the market. These molecules also showed negative drug-likeness values, pointing to the originality of these structures and theoretical feasibility on escaping of resistance mechanism and act against resistant strains. Thus, these eugenol derivatives may be considered as promising for the development of new treatments against bovine mastitis and future exploring on this purpose.
KMnO4-catalyzed chemoselective deprotection of acetate and controllable deacetylation-oxidation in one pot
Gurawa, Aakanksha,Kumar, Manoj,Rao, Dodla S.,Kashyap, Sudhir
supporting information, p. 16702 - 16707 (2020/10/27)
A novel and efficient protocol for chemoselective deacetylation under ambient conditions was developed using catalytic KMnO4. The stoichiometric use of KMnO4 highlighted the dual role of a heterogeneous oxidant enabling direct access to aromatic aldehydes in one-pot sequential deacetylation-oxidation. The reaction employed an alternative solvent system and allowed the clean transformation of benzyl acetate to sensitive aldehyde in a single step while preventing over-oxidation to acids. Use of inexpensive and readily accessible KMnO4 as an environmentally benign reagent and the ease of the reaction operation were particularly attractive, and enabled the controlled oxidation and facile cleavage of acetate in a preceding step. This journal is
Scalable green approach toward fragrant acetates
Puchl'Ová, Eva,Szolcsányi, Peter
, (2020/08/07)
The advantageous properties of ethylene glycol diacetate (EGDA) qualify it as a useful substitute for glycerol triacetate (GTA) for various green applications. We scrutinised the lipase-mediated acetylation of structurally diverse alcohols in neat EGDA furnishing the range of naturally occurring fragrant acetates. We found that such enzymatic system exhibits high reactivity and selectivity towards activated (homo) allylic and non-activated primary/secondary alcohols. This feature was utilised in the scalable multigram synthesis of fragrant (Z)-hex-3-en-1-yl acetate in 70percent yield. In addition, the Lipozyme 435/EGDA system was also found to be applicable for the chemo-selective acetylation of (hydroxyalkyl) phenols as well as for the kinetic resolution of chiral secondary alcohols. Lastly, its discrimination power was demonstrated in competitive experiments of equimolar mixtures of two isomeric alcohols. This enabled the practical synthesis of 1-pentyl acetate isolated as a single product in 68percent yield from the equimolar mixture of 1-pentanol and 3-pentanol.
Synthesis of eugenol derivatives and its anti-inflammatory activity against skin inflammation
Agarwal, Karishma,Ahmad, Ateeque,Bawankule, Dnyaneshwar Umrao,Gupta, Amit Chand,Maurya, Anil Kumar,Nooreen, Zulfa,Saxena, Archana,Tandon, Sudeep
, p. 251 - 260 (2019/01/04)
Eugenol is a phytochemical present in aromatic plants has generated considerable interest in the pharmaceutical industries mainly in cosmetics. A series of eugenol esters (ST1-ST7) and chloro eugenol (ST8) have been synthesized. The structures of newly synthesized compounds were confirmed by 1H and 13C NMR and mass spectrometry. In an effort to evaluate the pharmacological activity of eugenol derivatives, we explored its anti-inflammatory potential against skin inflammation using in-vitro and in-vivo bioassay. Synthesized derivatives significantly inhibited the production of pro-inflammatory cytokines against LPS-induced inflammation in macrophages. Among all derivatives, ST8 [Chloroeugenol (6-chloro, 2-methoxy-4-(prop-2-en-1-yl)-phenol)] exhibited most potent anti-inflammatory activity without any cytotoxic effect. We have further evaluated the efficacy and safety in in-vivo condition. ST8 exhibited significant anti-inflammatory activity against TPA-induced skin inflammation without any skin irritation effect on experimental animals. These findings suggested that ST8 may be a useful therapeutic candidate for the treatment of skin inflammation.
Palladium-Catalyzed Oxidative Allylation of Sulfoxonium Ylides: Regioselective Synthesis of Conjugated Dienones
Li, Chunsheng,Li, Meng,Zhong, Wentao,Jin, Yangbin,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
supporting information, p. 872 - 875 (2019/05/16)
The first examples of palladium-catalyzed allylic C-H oxidative allylation of sulfoxonium ylides to afford the corresponding conjugated dienones with moderate to good yields have been established. The features of this novel conversion include mild reaction conditions, wide substrate scope, and excellent regioselectivity.
Synthesis method of 4-hydroxycinnamaldehyde compound
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Paragraph 0028; 0029; 0030, (2018/03/26)
The invention relates to the field of organic synthesis and agricultural chemistry, and particularly discloses a synthesis method of a 4-hydroxycinnamaldehyde compound shown as a formula II. The synthesis method comprises the following steps: with 4-hydroxy-allylbenzene as a raw material, firstly performing hydroxyl protection, then with 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an oxidant and water (H2O) as a nucleophile, oxidizing an allyl group into alpha, beta-unsaturated aldehyde (namely, a cinnamaldehyde structure) under a relatively mild condition, and finally performing deprotection to obtain a target product. The invention elaborates a novel synthesis method of the 4-hydroxycinnamaldehyde compound. The novel synthesis method has the characteristics of no transition metalparticipation, a simple and mild reaction condition, high product yield and the like, and has a wide application prospect in the field of the agricultural chemistry, especially in plant science and bioenergy conversion.
