3663-82-9Relevant articles and documents
Mild Intramolecular Ring Opening of Oxetanes
Deratt, Lindsey G.,Lawson, Edward C.,Wang, Chao-Yuan,Kuduk, Scott D.
, p. 9642 - 9645 (2019)
Oxetanes have been increasingly used as stable motifs in medicinal chemistry as well as versatile synthetic intermediates. Herein, an intramolecular ring opening of oxetane carboxamides with mild nucleophiles, such as nitrogen heterocycles, is presented. The reaction proceeds under metal-free basic conditions which is highly unusual in ring opening reactions of oxetanes. Amide formation and oxetane ring opening/cyclization in a one-pot approach affords high levels of molecular complexity in a single step from simple, readily available substrates.
THE KINETICS AND MECHANISM(S) OF NUCLEOPHILIC ATTACK BY CATECHOLATE ANION ON EPIBROMOHYDRIN-d2
Cawley, John J.,Onat, Ediz
, p. 395 - 398 (1994)
The reaction which forms hydroxymethylbenzodioxane from epibromohydrin and catecholate anion was examined by ultraviolet spectroscopy for the kinetics and by proton nuclear magnetic resonance spectroscopy to follow the fate of CD2 from reactant to product.Over the practical temperature range it was found that both CH2 positions in the epihalohydrin are attacked by catecholate anion to give product.Therefore, the difference in energy for the two pathways was small.The individual rate constants were obtained from the total rate constants.Further, the individual ΔH(excit.) and ΔS(excit.) values were calculated.It was found that the pathway of higher ΔH(excit.) had the less negative ΔS(excit.), which explains the subtlety of two mechanisms being operative over the available temperature range.Interestingly, it proved impossible to prepare epibromohydrin with two deuteriums at only one position in what appeared to be a relatively straightforward synthesis.
One-pot preparation of chiral 2-vinyl-1,4-benzodioxane
Massacret, Magali,Goux, Catherine,Lhoste, Paul,Sinou, Denis
, p. 6093 - 6096 (1994)
2-Vinyl-1,4-benzodioxane was obtained with e.e. up to 45% by condensation of catechol and (Z)-2-butene-1,4-diylbis(methylcarbonate) in the presence of a catalytic amount of palladium(0) in association with chiral ligand such as BINAP.
Light-Promoted Nickel Catalysis: Etherification of Aryl Electrophiles with Alcohols Catalyzed by a NiII-Aryl Complex
Cao, Rui,Lai, Chu-Hui,Li, Gang,Liu, Fengyi,Lu, Huan-Huan,Wang, Chao,Xiao, Jianliang,Xue, Dong,Yang, Liu,Zhang, Wei
, p. 12714 - 12719 (2020/06/02)
A highly effective C?O coupling reaction of (hetero)aryl electrophiles with primary and secondary alcohols is reported. Catalyzed by a NiII-aryl complex under long-wave UV (390–395 nm) irradiation in the presence of a soluble amine base without any additional photosensitizer, the reaction enables the etherification of aryl bromides and aryl chlorides as well as sulfonates with a wide range of primary and secondary aliphatic alcohols, affording synthetically important ethers. Intramolecular C?O coupling is also possible. The reaction appears to proceed via a NiI–NiIII catalytic cycle.
An innovative synthesis pathway to benzodioxanes: The peculiar reactivity of glycerol carbonate and catechol
Tabanelli,Giliberti,Mazzoni,Cucciniello,Cavani
, p. 329 - 338 (2019/01/28)
A peculiar reactivity of glycerol carbonate (GlyC) as an innovative and highly reactive alkylating agent for phenolic compounds is investigated in this article. In particular, 2-hydroxymethyl-1,4-benzodioxane (HMB), a key intermediate for the pharmaceutical industry, has been selectively synthesized by the reaction of a slight excess of GlyC with catechol in the presence of a basic catalyst (NaOCH3, Na-mordenite, MgO), without requiring a reaction solvent. Both reagents have been quantitatively converted in just one hour at 170 °C with a HMB yield, up to 88%, in the presence of a homogeneous basic catalyst (NaOCH3). Notably, the main side product, the HMB isomer, may be an interesting intermediate for the synthesis of calone analogues, which are important scaffolds used in fragrances. A detailed mechanistic study, supported by kinetics, GC-MS, and HMBC NMR characterization, is also reported. Accordingly, this paper describes a completely innovative and greener synthesis pathway to benzodioxanes.
PROCESS FOR OBTAINING PHENOLIC DERIVATIVES BY USING GLYCEROL CARBONATE
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Page/Page column 17; 18; 19; 20; 21; 22; 23; 24, (2018/10/19)
It is disclosed a process for obtaining phenolic derivatives with high industrial interest in the pharmaceutical industry by using glycerol carbonate. Specifically, the process provides for a phenol substituted in position 2 to react with glycerol carbonate in the presence of a basic catalyst capable of activating the substituted phenol. The reaction can be carried out in the presence of a homogeneous catalyst or a heterogeneous catalyst, ensuring in any case good selectivity and high yields towards the desired product.
GC–MS study of thermochemical conversion of guaifenesin in the presence of 1-butyl-3-methylimidazolium-based ionic liquids
Hamid, Sharifah Bee Abd,Khaligh, Nader Ghaffari,Sharifi, Mahdieh,Johari, Suzaimi
, p. 4007 - 4021 (2017/06/20)
Thermochemical conversion of guaifenesin was performed in the presence of 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] ionic liquid at 80?°C within 2?h. After evaluating the effect of different parameters, such as protic and nonpro
A sulfuric acid guanidine lives synthesis method
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Paragraph 0024; 0025; 0030; 0031, (2017/08/26)
The invention belongs to the technical field of organic drug synthesis, and particularly relates to a guanoxan sulfate synthesis method. The method comprises steps as follows: 1), 2-hydroxymethyl-1,4-benzodioxane and thionyl chloride have a chlorination reaction under the condition of existence of a solvent I, and 2-chloromethyl-1,4-benzodioxane is obtained; 2), 2-chloromethyl-1,4-benzodioxane and guanidine are condensed under the condition of existence of alkali and a solvent II, guanoxan is obtained, guanoxan and sulfuric acid are salified, and a finished product guanoxan sulfate is obtained. According to the guanoxan sulfate synthesis method, technological synthesis steps are simple, a route is short, raw material toxicity is relatively lower, and the yield and the purity of the product are high.
Method for synthesizing doxazosin
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Paragraph 0063; 0068; 0069; 0070, (2017/01/12)
The invention discloses a method for synthesizing doxazosin and belongs to the technical field of chemical synthesis. According to the method, the doxazosin is synthesized by adopting a synthesis route, represented by formulae shown in the description, different from the conventional technologies, and thus a novel synthesis route is provided for preparing the doxazosin; and the method has the advantages of moderate conditions, simple and convenient steps and high yield, and the doxazosin can be obtained simply and efficiently.
Halogen bonding enhances activity in a series of dual 5-HT6/D2 ligands designed in a hybrid bioisostere generation/virtual screening protocol
Staroń, Jakub,Warszycki, Dawid,Kurczab, Rafa?,Sata?a, Grzegorz,Bugno, Ryszard,Hogendorf, Adam,Bojarski, Andrzej J.
, p. 54918 - 54925 (2016/07/06)
A novel hybrid bioisostere generation/virtual screening method combined with narrowing of chemical space through similarity to compounds that are active at the second target was successfully applied for the development of structurally new dual 5-HT6/D2 receptor ligands. Consequently, a series of derivatives of the found hit 1d (N-[2-(dimethylamino)ethyl]-N-(2-phenylethyl)aniline) was synthesized. The most active 5-HT6/D2 ligands also showed affinity for 5-HT7R and 5-HT2AR. The para-chloroaniline derivative was identified as a potent dual 5-HT6/5-HT7 receptor antagonist (Ki = 24 nM and Kb = 30 nM, Ki = 4 nM and Kb = 1.4 nM, respectively). In the case of halogen-containing compounds, interesting structure-activity relationships were observed at 5-HT6, D2 and 5-HT7 receptors, and the ligand-receptor complexes were subsequently examined using a molecular modelling approach that combined quantum-polarized ligand docking (QPLD) and Molecular-Mechanics-Generalized-Born/Surface Area (MM/GBSA) free-energy calculation, which permitted the identification of putative halogen binding pockets.
