4984-22-9Relevant academic research and scientific papers
Preparation method of metolachlor
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Paragraph 0066-0068, (2020/03/17)
The method comprises the following steps, reacting methanol and: propylene oxide to obtain (R)- methoxy - 2 2-ethyl aniline (R)- 1 - reacting the compound with, methyl - 6 6-ethylaniline to obtain I methyl - 222222227, by reacting I methyl-6-ethylaniline. 2 - The compound S - (-) - N - (R - shown) - 2 - is prepared by reacting the compound shown, with a sulfuryl chloride compound in a short, reaction step in a process, of reacting, with a chloroacetyl chloride compound in a short time of (S)- in a short time, The present, invention provides, a, method for producing metotilachlor in the. following steps: STR2715 STR7#
Homochiral Metal-Organic Cage for Gas Chromatographic Separations
Xie, Sheng-Ming,Fu, Nan,Li, Li,Yuan, Bao-Yan,Zhang, Jun-Hui,Li, Yan-Xia,Yuan, Li-Ming
, p. 9182 - 9188 (2018/07/21)
Metal-organic cages (MOCs) as a new type of porous material with well-defined cavities were extensively pursued because of their relative ease of synthesis and their potential applications in host-guest chemistry, molecular recognition, separation, catalysis, gas storage, and drug delivery. Here, we first reported that a homochiral MOC [Zn3L2] is explored to fabricate [Zn3L2] coated capillary column for high-resolution gas chromatographic separation of a wide range of analytes, including n-alkanes, polycyclic aromatic hydrocarbons, and positional isomers, especially for racemates. Various kinds of racemates such as alcohols, diols, epoxides, ethers, halohydrocarbons, and esters were separated with good enantioselectivity and reproducibility on the [Zn3L2] coated capillary column. The fabricated [Zn3L2] coated capillary column exhibited significant chiral recognition complementary to that of a commercial β-DEX 120 column and our recently reported homochiral porous organic cage CC3-R coated column. The results show that the homochiral MOCs will be very attractive as a new type of chiral selector in separation science.
Optimized Synthetic Route for Enantioselective Preparation of (S)-Metolachlor from Commercially Available (R)-Propylene Oxide
Yang, Peng,Wang, Xiao,Peng, Lin,Chen, Feng,Tian, Fang,Tang, Chao-Zhe,Wang, Li-Xin
, p. 1682 - 1688 (2017/10/25)
An enantioselective preparation of (S)-metolachlor has been accomplished. The synthetic route featured the asymmetric preparation of chiral intermediates and the final (S)-metolachlor from commercially available (R)-propylene oxide and a key Fukuyama's process. The key steps, control points, separation purifications, and the whole process are optimized, and the target compound has been successfully prepared in five steps in 51-55% overall yield with excellent enantioselectivity (99% ee) up to a 30 g scale. By judicious choice of synthetic route and selection of starting materials and intermediates, no column chromatographic methods are needed for the separation and purification of the intermediates and the final products. The same strategy was extended as a general method for a series of pesticides and herbicide analogs of Metalaxyl-M and Dimethenamid-P.
Application of homochiral alkylated organic cages as chiral stationary phases for molecular separations by capillary gas chromatography
Xie, Shengming,Zhang, Junhui,Fu, Nan,Wang, Bangjin,Hu, Cong,Yuan, Liming
, (2016/12/03)
Molecular organic cage compounds have attracted considerable attention due to their potential applications in gas storage, catalysis, chemical sensing, molecular separations, etc. In this study, a homochiral pentyl cage compound was synthesized from a condensation reaction of (S,S)-1,2-pentyl-1,2-diaminoethane and 1,3,5-triformylbenzene. The imine-linked pentyl cage diluted with a polysiloxane (OV-1701) was explored as a novel stationary phase for high-resolution gas chromatographic separation of organic compounds. Some positional isomers were baseline separated on the pentyl cage-coated capillary column. In particular, various types of enantiomers including chiral alcohols, esters, ethers and epoxides can be resolved without derivatization on the pentyl cage-coated capillary column. The reproducibility of the pentyl cage-coated capillary column for separation was investigated using nitrochlorobenzene and styrene oxide as analytes. The results indicate that the column has good stability and separation reproducibility after being repeatedly used. This work demonstrates that molecular organic cage compounds could become a novel class of chiral separation media in the near future.
Ketone-alcohol hydrogen-transfer equilibria: Is the biooxidation of halohydrins blocked?
Bisogno, Fabricio R.,Garcia-Urdiales, Eduardo,Valdes, Haydee,Lavandera, Ivan,Kroutil, Wolfgang,Suarez, Dimas,Gotor, Vicente
supporting information; experimental part, p. 11012 - 11019 (2010/11/18)
To ensure the quasi-irreversibility of the oxidation of alcohols coupled with the reduction of ketones in a hydrogen-transfer (HT) fashion, stoichiometric amounts of a-halo carbonyl compounds have been employed as hydrogen acceptors. The reason that these substrates lead to quasi-quantitative conversions has been tacitly attributed to both thermodynamic and kinetic effects. To provide a clear rationale for this behavior, we investigate herein the redox equilibrium of a selected series of ketones and 2-propanol by undertaking a study that combines experimental and theoretical approaches. First, the activity of the (R)-specific alcohol dehydrogenase from Lactobacillus brevis (LBADH) with these substrates was studied. The docking of acetophenone/(R)-l-phenyethanol and a-chloroacetophenone/(S)-2-chloro- lphenylethanol in the active site of the enzyme confirms that there seems to be no structural reason for the lack of reactivity of halohydrins. This assumption is confirmed by the fact that the corresponding aluminum-catalyzed Meerwein-Ponndorf-Verley-Oppenauer (MPVO) reactions afford similar conversions to those obtained with LBADH, showing that the observed reactivity is independent of the catalyst employed. While the initial rates of the enzymatic reductions and the IR v(C=0) values contradict the general belief that electron-withdrawing groups increase the electrophilicity of the carbonyl group, the calculated βG values of the isodesmic redox transformations of these series of ketones/alcohols with 2-propanol/acetone support the thermodynamic control of the reaction. As a result, a general method to predict the degree of conversion obtained in the HT-reduction process of a given ketone based on the IR absorption band of the carbonyl group is proposed, and a strategy to achieve the HT oxidation of halohydrins is also shown.
Generation of a solid Bronsted acid site in a chiral framework
Ingleson, Michael J.,Barrio, Jorge Perez,Bacsa, John,Dickinson, Calum,Park, Hyunsoo,Rosseinsky, Matthew J.
, p. 1287 - 1289 (2008/12/21)
Protonation of chiral porous materials introduces a Bronsted acid centre, the structure of which is unique to the heterogeneous phase requiring pore wall confinement for stable isolation. The Royal Society of Chemistry.
A high-throughput-screening method for the identification of active and enantioselective hydrolases
Baumann, Markus,Stuermer, Rainer,Bornscheuer, Uwe T.
, p. 4201 - 4204 (2007/10/03)
A rapid and reliable test for the determination of hydrolase activity and enantioselectivity comprises the conversion of acetic acid released from acetates to NADH by using a commercially available enzymatic test-kit (see scheme). The NAHDH is spectrophotometrically quantified in a microtiter plate format.
(β-amino alcohol)(arene)ruthenium(II)-catalyzed asymmetric transfer hydrogenation of functionalized ketones - Scope, isolation of the catalytic intermediates, and deactivation processes
Everaere, Kathelyne,Mortreux, André,Bulliard, Michel,Brussee, Johannes,Van Der Gen, Arne,Nowogrocki, Guy,Carpentier, Jean-Fran?ois
, p. 275 - 291 (2007/10/03)
The asymmetric transfer hydrogenation of functionalized ketones with (β-amino alcohol)(arene)RuII catalysts using 2-propanol as the hydrogen source has been studied. The structure of the catalyst has been systematically screened using a wide variety of [(η6-arene)RuCl2]2 complexes and β-amino alcohols R1CH(OH)CHR2NHR3, some of which were specifically designed for optimized performance, e.g. (1S,2R)-N-(4-biphenylmethyl)norephedrine (9ο). The efficiencies of the catalytic combinations have been evaluated in the reduction of β-oxo esters and ketones bearing heteroatoms at the α-position. The catalyst precursor [{η6-p-cymene}{η2-N,O-(9ο)}RuCl] (35), the 16-electron true catalyst [{η6-p-cymene}{η2-N,O-(9ο1-) }Ru] (36), and the hydride [{η6-p-cymene}{η2-N,O-(9ο)}RuH] (37) involved in the reduction process have been isolated, characterized by NMR and ESI-MS, as well as by X-ray crystallography in the case of 35, and their reactivities have been investigated. The results reveal two general trends regarding this catalytic process: (1) the apparent reaction rate and the enantioselectivity are largely controlled by the nature of the amine functionality of the chiral ligand and the arene ring of the RuII precursor; (2) side reactions occur between the ketone substrate and the active catalytic species that affect the concentration of the latter and consequently the apparent rate; the formation of inactive (β-diketonato)RuII complexes is demonstrated in the case of β-oxo esters.
Pyrazolopyrimidinone cGMP PDE5 inhibitors for the treatment of sexual dysfunction
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, (2008/06/13)
Compounds of the formulae (IA) and (IB): wherein R1is C1to C3alkyl optionally substituted with phenyl, Het or a N-linked heterocyclic group selected from piperidinyl and morpholinyl; wherein said phenyl group is optionally substituted by one or more substitutents selected from C1to C4alkoxy; halo; CN; CF3; OCF3or C1to C4alkyl wherein said C1to C4alkyl group is optionally substituted by C1to C4haloalkyl or haloalkoxy either of which is substituted by one or more halo atoms; R2is C1to C6alkyl and R13is OR3or NR5R6, or pharmaceutically or veterinarily acceptable salts thereof, or pharmaceutically or veterinarily acceptable solvates of either entity are potent and selective inhibitors of type 5 cyclic guanosine 3′,5′-monophosphate phosphodiesterase (cGMP PDE5) and have utility in the treatment of, inter alia, male erectile dysfunction (MED) and female sexual dysfunction (FSD).
Rapid screening of hydrolases for the enantioselective conversion of 'difficult-to-resolve' substrates
Baumann, Markus,Hauer, Bernhard H.,Bornscheuer, Uwe T.
, p. 4781 - 4790 (2007/10/03)
Hydrolases showing high enantioselectivity towards three racemic alcohols (1-methoxy-2-propanol, 3-hydroxy-tetrahydrofuran, 3-butyn-2-ol) and pantolactone were identified by a step-wise screening procedure. Initially, those biocatalysts, which exhibited hydrolytic activity towards the corresponding acetates or butyrates, were selected out of >100 enzymes. Here, rapid screening was performed in a pH-indicator-based format in microtiter plates. Subsequently, enantioselectivity of active hydrolases was determined in small scale reactions (～1 mg substrate per reaction) by means of gas chromatography using chiral columns. Enzymes exhibiting highest enantioselectivities were then chosen for preparative scale resolution. Using this strategy, at least one suitable hydrolase was found for 3 out of the 4 model compounds examined, allowing efficient kinetic resolution. Moreover, in all cases enantiocomplementary enzymes were identified thus enabling access to both enantiomers of all substrates.
