- A mild and practical method for deprotection of aryl methyl/benzyl/allyl ethers with HPPh2andtBuOK
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A general method for the demethylation, debenzylation, and deallylation of aryl ethers using HPPh2andtBuOK is reported. The reaction features mild and metal-free reaction conditions, broad substrate scope, good functional group compatibility, and high chemical selectivity towards aryl ethers over aliphatic structures. Notably, this approach is competent to selectively deprotect the allyl or benzyl group, making it a general and practical method in organic synthesis.
- Pan, Wenjing,Li, Chenchen,Zhu, Haoyin,Li, Fangfang,Li, Tao,Zhao, Wanxiang
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p. 7633 - 7640
(2021/09/22)
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- Preparation method of p-(2-methoxyl)ethyl phenol
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The invention discloses a preparation method of p-(2-methoxyl) ethyl phenol. According to the preparation method, p-chlorophenol is taken as the raw material, after etherification reactions, p-chlorophenol with a protected phenolic hydroxyl group is obtained, and after Grignard reactions, chlorination reactions, and methoxyl substitution reactions, p-(2-methoxyl)ethyl phenol is generated. The provided preparation method has the advantages of easily available raw materials, mild reaction conditions, high safety coefficient, strong operability, simple technology, easy industrialization, high product purity, and stable quality. The prepared p-(2-methoxyl)ethyl phenol totally meets the using requirements of medical intermediates.
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- Iodonitrene in Action: Direct Transformation of Amino Acids into Terminal Diazirines and 15N2-Diazirines and Their Application as Hyperpolarized Markers
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A one-pot metal-free conversion of unprotected amino acids to terminal diazirines has been developed using phenyliodonium diacetate (PIDA) and ammonia. This PIDA-mediated transformation occurs via three consecutive reactions and involves an iodonitrene intermediate. This method is tolerant to most functional groups found on the lateral chain of amino acids, it is operationally simple, and it can be scaled up to provide multigram quantities of diazirine. Interestingly, we also demonstrated that this transformation could be applied to dipeptides without racemization. Furthermore, 14N2 and 15N2 isotopomers can be obtained, emphasizing a key trans-imination step when using 15NH3. In addition, we report the first experimental observation of 14N/15N isotopomers directly creating an asymmetric carbon. Finally, the 15N2-diazirine from l-tyrosine was hyperpolarized by a parahydrogen-based method (SABRE-SHEATH), demonstrating the products' utility as hyperpolarized molecular tag.
- Colell, Johannes F. P.,Franck, Xavier,Glachet, Thomas,Marzag, Hamid,Reboul, Vincent,Saraiva Rosa, Nathalie,Theis, Thomas,Warren, Warren S.,Zhang, Guannan
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- Preparation method of metoprolol intermittent
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The invention belongs to the field of organic synthesis of medicines, and particularly relates to a preparation method of an intermittent of a medicine metoprolol for treating hypertension. A synthesis route of the method comprises the steps that in the presence of a palladium catalyst and a phosphine ligand, p-bromophenol is reacted with methyl vinyl ether to generate 4-(2-methoxy vinyl)phenol; the 4-(2-methoxy vinyl)phenol is subjected to hydrogenation in the presence of a palladium carbon catalyst to obtain the target product 4-(2-methoxyethyl)phenol. The reaction steps are short, the raw materials are cheap and easy to obtain, a technology is simple, operation is convenient, and no special reaction conditions are needed, so that the method is more suitable for industrial production.
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Paragraph 0019; 0038; 0041-0042; 0043; 0046-0047
(2019/03/08)
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- To the methoxy ethyl phenol synthesis method (by machine translation)
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The invention discloses a method for synthesizing methoxy ethyl phenol, to the chlorophenol as the starting material, through the phenolic hydroxyl protection, format reaction, methylation and hydrogenation debenzylation reaction to obtain the target product to the methoxy ethyl phenol process, the methylation reaction is just a simple filtering operation that can be used for the next step reaction, without any other operation. This invention adopts the [...] as the starting material to synthesize to methoxy ethyl phenol, reduce the difficulty of after treatment, reduce the reaction time, the product has high purity, high yield, good stability of the product. (by machine translation)
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Paragraph 0037-0038
(2018/11/04)
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- Synthesis method for preparing metoprolol intermediate
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A synthesis method for preparing a metoprolol intermediate comprises the following steps: 1, dissolving phenol and chloroacetyl chloride in a dichloroethane solvent, adding aluminum trichloride as a catalyst, stirring for reaction to generate 4-chloracetyl phenol; 2, dissolving the 4-chloracetyl phenol generated by the reaction of the step 1 in methanol, adding methanol sodium, starting a stirrer for stirring for reaction to generate 4-(2'-methoxy acetyl) phenol; 3, adding the 4-(2'-methoxy acetyl) phenol generated by the reaction of the step 2 into a reactor, adding a catalyst, adding a reductant, starting stirring, and heating for reaction to generate intermediate 4-(2 '-methoxy ethyl) phenol. The advantages are as follows: the method for preparation of the 4-(2 '-methoxy ethyl) phenol is simple in operation, mild in conditions, environmental friendly, low in cost, and is suitable for industrial production, Raney nickel can be reused, the reaction yield reaches 86%, and the purity reaches 98% or above.
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- Easy eco-friendly phenonium ion production from phenethyl alcohols in dimethyl carbonate
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An efficient and simple one-pot procedure for selective etherification of 2-aryl-ethylalcohols has been achieved through Amberlyst 15-catalyzed reaction in dimethyl carbonate (DMC). Moreover, the polymer catalyst could be recovered and reused with no effect on its activity. The reaction mechanism involves the formation of phenonium ion which has been demonstrated by a C-C bond forming reaction. Theoretical studies are in agreement with and thus explain experimental results.
- Barontini,Proietti Silvestri,Nardi,Bovicelli,Pari,Gallucci,Spezia,Righi
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supporting information
p. 5004 - 5006
(2013/08/28)
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- Preparation and antioxidant activity of tyrosyl and homovanillyl ethers
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Preparation of tyrosyl and homovanillyl lipophilic derivatives was carried out as a response to the food industry's increasing demand for new synthetic lipophilic antioxidants. Tyrosyl and homovanillyl ethers were synthesized in high yields by a three-step procedure starting from tyrosol (Ty) and homovanillic alcohol (HMV). The antioxidant activity of these new series of alkyl tyrosyl and homovanillyl ethers was evaluated by the Rancimat test in a lipophilic food matrix and by the FRAP, ABTS and ORAC assays and compared to free Ty and HMV as well as two antioxidants widely used in the food industry, butylhydroxytoluene (BHT) and α-tocopherol. The results pointed out the higher activity of homovanillyl series in comparison with tyrosyl series with all the assayed methods. However, while both synthetic series were less antioxidant than BHT and α-tocopherol in a lipophilic matrix after their Rancimat test evaluation, homovanillyl alkyl ethers showed the best reducing power and radical scavenging activity of all evaluated compounds. This batch of synthetic lipophilic compounds, derived from biologically active compounds such as Ty and HMV, provide interesting and potentially bioactive compounds.
- Madrona,Pereira-Caro,Bravo,Mateos,Espartero
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experimental part
p. 1169 - 1178
(2012/05/05)
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- Thermolysis of 4-(ω-hydroxyalkyl)-2,6-di-tert-butylphenols
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The process of thermolysis of tert-butylated hydroxyalkyl phenols includes de-tert-butylation, etherification, and fragmentation of the hydroxyalkyl group. On the basis of the proposed schemes of the mechanism of thermal de-tert-butylation the path of the search for catalysts for the synthesis of 4-hydroxyalkylphenols is defined and transformations of the by-products into biologically active substances were considered.
- Krysin,Egorova,Vasil'Ev
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experimental part
p. 275 - 283
(2010/07/15)
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- Facile preparation of polymer-supported methyl sulfonate and its recyclable use for methylation of carboxylic acids and amines
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A simple and efficient one-pot procedure for the preparation of polymer-supported methyl sulfonate from the reaction of polymer-supported sulfonic acid with trimethyl orthoacetate was achieved, and it could be successfully used for efficient methylation of carboxylic acids, phosphonic acids, sulfinic acids, amines, thiol, and phenol. Moreover, the polymer reagent could be recovered, regenerated, and reused easily for the same reactions. Georg Thieme Verlag Stuttgart.
- Yoshino, Tomonori,Togo, Hideo
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p. 517 - 519
(2007/10/03)
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- Synthesis and cardiovascular activity of metoprolol analogues
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The synthesis of four novel analogues of metoprolol, a well-known β1-blocker used to reduce arterial blood pressure, is described. The preparation of (2S,2′S)-7, (2R,2′S)-7, (2R,2′R)-8, and (2S,2′R)-8 was based on the reaction of racemic 2-[4-(2′- methoxyethyl)-phenoxymethyl]-oxirane (4) with (R)- or (S)-2-amino-1-butanol. Salient characteristics of analogues 7 and 8 relative to metoprolol are the incorporation of an additional stereogenic center, as well as a methyl group and a hydroxyl function on the nitrogen-containing chain. These novel derivatives present significant hypotensive and bradycardiac activity, although no blocking action toward β1 and β2 adrenergic receptor.
- Melgar-Fernandez, Roberto,Demare, Patricia,Hong, Enrique,Rosas, Miguel Angel,Escalante, Jaime,Munoz-Muniz, Omar,Juaristi, Eusebio,Regla, Ignacio
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p. 191 - 194
(2007/10/03)
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- Process for preparing phenethanol ethers
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Substituted phenethanol ethers are prepared in useful yields by the etherification of corresponding substituted phenethyl alcohols with aliphatic primary alcohols. The etherification is carried out by reacting a substituted phenethyl alcohol with an aliphatic primary alcohol in the presence of an acid catalyst at a temperature of at least about 75° C.
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- Method for producing 4-(2'-methoxyethyl)phenol
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The invention provides a method for producing 4-(2'-methoxyethyl)phenol by brominating 4-hydroxyacetophenone to produce alpha-bromo-5-hydroxyacetophenone, and then causing a methoxide-bromide exchange to thereby produce alpha-methoxy-4-hydroxyacetophenone; and then conducting a single step reduction of alpha-methoxy-4-hydroxyacetophenone with at least two equivalents of hydrogen per equivalent of alpha-methoxy-4-hydroxyacetophenone in the presence of a hydrogenation catalyst to thereby directly produce 4-(2'-methoxyethyl)phenol.
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- PROCESS FOR PREPARING PHENETHANOL ETHERS BY THE REDUCTION OF CORRESPONDING PHENYLGLYOXAL ACETALS
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Substituted phenethanol ethers are prepared by the catalytic reduction of corresponding substituted phenylglyoxal acetals. The catalytic reduction is carried out by reacting a substituted phenylglyoxal acetal with hydrogen in the presence of an acid catalyst and a metal catalyst. Certain substituted phenylglyoxal acetals, and more particularly, 4-hydroxyphenylglyoxal dialkyl acetals are prepared by reacting 4-hydroxyacetophenone with a primary or a secondary alkyl alcohol in the presence of a hydrogen ion (H+) source and a nitrosonium ion (NO+) source.
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- A New Route to (+/-) Metoprolol
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Synthesis of 4-(2-methoxyethyl)phenol (5) from phenol is described.The derived aryloxyallyl ether (6) is converted into (+/-)-metoprolol (10) by involving dihydroxylation reaction with OsO4 and NMO.
- Gurjar, M.K.,Joshi, Shreerang V,Sastry, B.S.,Rao, A V Rama
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p. 3489 - 3496
(2007/10/02)
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- Synthesis and Physical Properties of Alkoxymethylene Substituted Phenyl Cyclohexanecarboxylates
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The homologous series of 4-alkoxymethylene-substituted-phenyl 4'-alkylcyclohexanecarboxylates are prepared.And their transition temperatures, bulk viscosities and birefringences have been measured comparing with the series of 4-alkoxy-substituted-phenyl 4'-alkylcyclohexanecarboxylates.The differences between the alkoxymethylene-substituted series and alkoxy-substituted series are discussed.Alkoxymethylene groups contribute to lowering the transition temperatures, and also reducing the bulk viscosities and optical anisotropy compared to the alkoxy groups as terminal groups of mesogens.This is apparently due to the higher flexibility of the alkoxymethylene groups, which affected the packing of molecules.
- Kitamura, Teruo,Mukoh, Akio,Era, Susumu,Fujii, Tsunenori
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p. 231 - 248
(2007/10/02)
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- The evaluation of a biogenetically based approach to the synthesis of octahydro-1H-benzofuro[3,2-e]isoquinolines
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A potential synthetic route to octahydro-1H-benzofuro[3,2-e]isoquinoline derivatives by intermolecular oxidative phenolic coupling has been studied. A variety of successful coupling reactions have been effected between 2-naphthol or 4-t-butylphenol and p-cresol, 2-(p-hydroxyphenyl)ethanol, 3,4-dimethylphenol, 5-indanol and 6-hydroxytetralin, but 2-acetyl-7-hydroxytetrahydroisoquinoline failed to participate in such reactions.
- Ajao,Bird,Chauhan
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p. 1367 - 1372
(2007/10/02)
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- A NEW ROUTE TO 4-(2-METHOXYETHYL)PHENOL VIA PALLADIUM-CATALYSED ARYLATION OF METHYL VINYL ETHER
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Palladium on charcoal-catalysed reaction of methyl vinyl ether with 4-bromonitrobenzene, followed by hydrogenation and subsequent diazotation afforded 4-(2-methoxyethyl)phenol in 47percent total yield.
- Hallberg, Anders,Westfelt, Lars,Andersson, Carl-Magnus
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p. 1131 - 1136
(2007/10/02)
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- STUDY OF NEW LIQUID CRYSTAL MATERIALS (II): SYNTHESIS AND MESOMORPHIC PROPERTIES OF ALKOXYMETHYLENE SUBSTITUTED PHENYL CYCLOHEXANECARBOXYLATES.
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The properties of alkoxymethylene-substituted-phenyl alkylcyclohexanecarboxylates are described. Such phenyl cyclohexanecarboxylates exhibit either a monotropic or an enantiotropic nematic phase. Their clearing points were lower than those of alkoxy-substituted-phenyl alkylcyclohexanecarboxylates, an effect considered to be due to the flexibility of the alkoxymethylene groups.
- Kitamura,Mukoh,Era
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p. 319 - 324
(2007/10/02)
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