6290-37-5Relevant academic research and scientific papers
Further evidence of extensive pulmonary first-pass ester hydrolysis after airways administration in rats
Dickinson,Seville,Taylor
, p. 441 - 445 (2000)
The aim of this study was to synthesize an ester with low lipophilicity, and to use this ester to further investigate pre-absorptive pulmonary first-pass metabolism. Hexanoic acid phenethyl ester was synthesized by reacting 2-phenylethanol with hexanoyl chloride. Pre-absorptive first-pass metabolism was assessed by comparing the areas under the blood concentration-time curves after intra-arterial administration of the hexanoic acid phenethyl ester with those after intratracheal instillation. Hexanoic acid phenethyl ester experienced extensive first-pass metabolism (53% of the absorbed dose) before or during absorption. This and earlier data suggests that the extent of this first-pass extraction is dependent on the physicochemical properties of the ester and in particular whether a compound experiences diffusion-limited absorption. Pre-absorptive pulmonary first-pass metabolism of compounds whose absorption iS diffusion-rate limited may be extensive even when pulmonary enzyme expression is low. This has consequences for the systemic delivery of drugs and in particular esters via the lungs.
Aldehyde effect and ligand discovery in Ru-catalyzed dehydrogenative cross-coupling of alcohols to esters
Jiang, Xiaolin,Zhang, Jiahui,Zhao, Dongmei,Li, Yuehui
, p. 2797 - 2800 (2019/03/27)
The presence of different aldehydes is found to have a significant influence on the catalytic performance when using PN(H)P type ligands for dehydrogenation of alcohols. Accordingly, hybrid multi-dentate ligands were discovered based on an oxygen-transfer alkylation of PNP ligands by aldehydes. The relevant Ru-PNN(PO) system provided the desired unsymmetrical esters in good yields via acceptorless dehydrogenation of alcohols. Hydrogen bonding interactions between the phosphine oxide moieties and alcohol substrates likely assisted the observed high chemoselectivity.
Transfer Hydro-dehalogenation of Organic Halides Catalyzed by Ruthenium(II) Complex
You, Tingjie,Wang, Zhenrong,Chen, Jiajia,Xia, Yuanzhi
, p. 1340 - 1346 (2017/02/10)
A simple and efficient Ru(II)-catalyzed transfer hydro-dehalogenation of organic halides using 2-propanol solvent as the hydride source was reported. This methodology is applicable for hydro-dehalogenation of a variety of aromatic halides and α-haloesters and amides without additional ligand, and quantitative yields were achieved in many cases. The potential synthetic application of this method was demonstrated by efficient gram-scale transformation with catalyst loading as low as 0.5 mol %.
Reductive dehalogenation method of organic halide
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Paragraph 0081; 0082; 0083; 0084; 0085; 0086, (2017/08/28)
The invention discloses a reductive dehalogenation method of an organic halide. In the inert gas atmosphere, the organic halide shown as the formula I or the formula II is subjected to reductive dehalogenation to generate an organic compound shown as the formula III or the formula IV (the formulas are shown as the description) in the presence of a catalyst, alkali and a solvent, wherein the reaction temperature is controlled to 90-100 DEG C. The reductive dehalogenation method has the advantages that the range of substrates is widened; the solvent in use does not need extra phosphorous ligands, the price is relatively cheap, and the consumption can be greatly reduced to 0.1 mol%; the solvent in use serves as a hydrogen source and reacts, the operation is simple, a lot reactions can reach quantitative yields, and when the reactions are scaled up to gram level reactions, almost quantitative yields can still be achieved.
Recyclable hypervalent iodine(III) reagent iodosodilactone as an efficient coupling reagent for direct esterification, amidation, and peptide coupling
Tian, Jun,Gao, Wen-Chao,Zhou, Dong-Mei,Zhang, Chi
supporting information; experimental part, p. 3020 - 3023 (2012/08/07)
A hypervalent iodine(III) reagent plays a novel role as an efficient coupling reagent to promote the direct condensation between carboxylic acids and alcohols or amines to provide esters, macrocyclic lactones, amides, as well as peptides without racemization. The regeneration of iodosodilactone (1) can also be readily achieved. The intermediate acyloxyphosphonium ion C from the activation of a carboxylic acid is thought to be involved in the present esterification reaction.
Characterization of aroma compounds of Chinese "Wuliangye" and "Jiannanchun" liquors by aroma extract dilution analysis
Fan, Wenlai,Qian, Michael C.
, p. 2695 - 2704 (2007/10/03)
Aroma compounds in Chinese "Wuliangye" liquor were identified by gas chromatography-olfactometry (GC-O) after fractionation. A total of 132 odorants were detected by GC-O in Wuliangye liquor on DB-wax and DB-5 columns. Of these, 126 aromas were identified by GC-mass spectrometry (MS). Aroma extract dilution analysis (AEDA) was further employed to identify the most important aroma compounds in "Wuliangye" and "Jiannanchun" liquors. The results showed that esters could be the most important class, especially ethyl esters. Various alcohols, aldehydes, acetals, alkylpyrazines, furan derivatives, lactones, and sulfur-containing and phenolic compounds were also found to be important. On the basis of flavor dilution (FD) values, the most important aroma compounds in Wuliangye and Jiannanchun liquors could be ethyl butanoate, ethyl pentanoate, ethyl hexanoate, ethyl octanoate, butyl hexanoate, ethyl 3-methylbutanoate, hexanoic acid, and 1,1-diethoxy-3-methylbutane (FD ≥ 1024). These compounds contributed to fruity, floral, and apple- and pineapple-like aromas with the exception of hexanoic acid, which imparts a sweaty note. Several pyrazines, including 2,5-dimethyl-3-ethylpyrazine, 2-ethyl-6-methylpyrazine, 2,6-dimethylpyrazine, 2,3,5-tri-methylpyrazine, and 3,5-dimethyl-2-pentylpyrazine, were identified in these two liquors. Although further quantitative analysis is required, it seems that most of these pyrazine compounds had higher FD values in Wuliangye than in Jiannanchun liquor, thus imparting stronger nutty, baked, and roasted notes in Wuliangye liquor.
Zn(ClO4)2·6H2O as a Powerful Catalyst for a Practical Acylation of Alcohols with Acid Anhydrides
Bartoli, Giuseppe,Bosco, Marcella,Dalpozzo, Renato,Marcantoni, Enrico,Massaccesi, Massimo,Sambri, Letizia
, p. 4611 - 4617 (2007/10/03)
A new protocol for the acylation of alcohols with anhydrides in the presence of Zn(ClO4)2·6H2O as the catalyst is reported. The activity of Zn(ClO4)2· 6H2O has been proven to be superior to that exerted by dry Mg(ClO4)2 and by metal triflates. Its efficiency allows reactions between poorly reactive substrates, such as sterically hindered tertiary alcohols and aromatic anhydrides, All of the reactions were carried out at a 1:1.05 alcohol/anhydride ratio. These conditions are extremely convenient from a practical and economic point of view, since they avoid wasting reagents and allow a simple workup procedure. The catalytic action of Zn(ClO4)2·6H2O is so specific for the activation of the anhydrides, that acid-sensitive functionalities and the stereochemical configuration of the starting materials remain unaltered in the esterification process. In all cases, the acylated products are quantitatively obtained in pure form. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
N,N,N',N'-TETRAMETHYLCHLOROFORMAMIDINIUM CHLORIDE AS AN EFFICIENT CONDENSATION REAGENT FOR A NOVEL ESTERIFICATION APPLICABLE TO THE MACROLIDE SYNTHESIS
Fujisawa, Tamotsu,Mori, Toshiki,Fukumoto, Kazumasa,Sato, Toshio
, p. 1891 - 1894 (2007/10/02)
N,N,N',N'-Tetramethylchloroformamidinium chloride, prepared easily from N,N,N',N'-tetramethylurea and oxalyl chloride, is found to be an efficient condensation reagent for an esterification of carboxylic acids with alcohols umder mild conditions in one-pot procedure, and the reagent is applied to the lactonization for macrolide synthesis from ω-hydroxycarboxylic acids.
