23981-80-8Relevant articles and documents
Racemization and hydrolysis of (S)-naproxen 2,2,2-trifluoroethyl ester in non-polar solvents by strong neutral bases: Implication for ion-pair kinetic basicity and hydrolysis
Lin, Man-Yuan,Lay, Eddy,Wen, Wen-Yen,Dewi, Hamza,Cheng, Yu-Chi,Tsai, Shau-Wei
, p. 387 - 392 (2004)
By using strong neutral bases as catalyst, a detailed investigation of the racemization of (S)-naproxen 2,2,2-trifluoroethyl ester was conducted in the non-polar solvents isooctane, cyclohexane and n-hexane. The second-order interconversion constant kint* as representing the ion-pair kinetic basicity in isooctane was first estimated and correlated with the equilibrium ion-pair basicity pKip in tetrahydrofuran, giving slopes of 0.768 and 0.689 for non-phosphazene and phosphazene bases, respectively, in the Bronsted correlations. The result was further compared with that for (S)-naproxen 2,2,2-trifluoroethyl thioester, showing about a 1-2 orders of magnitude enhancement of kint* for the corresponding thio-containing analogue. A smaller influence of non-polar solvents (i.e. isooctane, n-hexane and cyclohexane) on kint* was found. Kinetic analysis of the racemization and hydrolysis of (S)-naproxen 2,2,2-trifluoroethyl ester in isooctane and n-hexane containing 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene and water suggests nucleophilic hydrolysis by the base, where the breakdown of tetrahedral intermediates I R1 and IS1 is the rate-limiting step and the hydrolysis constant khy is in proportion to the product of base and ion-pair concentrations. Copyright 2004 John Wiley & Sons, Ltd.
Simple synthetic approach to arylacetic NSAIAs via TosMIC procedure
Di Santo,Costi,Massa,Artico
, p. 787 - 793 (1995)
Preparation of 1-methylpyrrole-2-acetonitrile, 1-methyl-5-(4-methylbenzoyl) pyrrole-2-acetonitrile and 2-(6-methoxy-2-naphthyl)propionitrile by treatment of 1-methylpyrrole-2-carboxaldehyde, 1-methyl-5-(4-methylbenzoyl)pyrrole-2-carboxaldehyde and, respectively, 6-methoxy-2-acetylnaphthalene with tosylmethylisocyanide (TosMIC) is described. This one-step synthetic procedure is very useful to obtain the nitrile precursors of tolmetin and naproxen, two clinically important non-steroidal antiinflammatory agents (NSAIAs).
Preparation of One-Pot Immobilized Lipase with Fe3O4 Nanoparticles Into Metal-Organic Framework For Enantioselective Hydrolysis of (R,S)-Naproxen Methyl Ester
Ozyilmaz, Elif,Ascioglu, Sebahat,Yilmaz, Mustafa
, p. 3687 - 3694 (2021/06/25)
Immobilization of enzyme to magnetic metal-organic frameworks (MOF) can preserve biological functionality in harsh environments to increase enzymes activity, stability, and improve reusability. The magnetic Fe3O4 nanoparticles were treated with calix[4]arene tetracarboxylic acid (Calix) and Candida rugosa lipase (CRL), and then encapsulated into the zeolitic imidazole framework-8 (Fe3O4@Calix-ZIF-8@CRL). The lipase activity data of Fe3O4@Calix-ZIF-8@CRL was 2.88 times higher than that of the Fe3O4@ZIF-8@CRL (without Calix). The catalytic properties of immobilized lipases were studied on the enantioselective hydrolysis of R/S-naproxen methyl ester. It was also observed that Fe3O4@Calix-ZIF-8@CRL has excellent enantioselectivity (E=371) compared to Fe3O4@ZIF-8@CRL (E=131). Furthermore, Fe3O4@Calix-ZIF-8@CRL was seen to still retain 30 % of the conversion rate after the fifth reuse. This work may also be useful for the pharmaceutical industry due to the increased reusability and stability of enzymes, the enantiomeric selectivity exhibited by MOF-enzyme biocomposites, and the significant differences in the biological activities of the enantiomers.
Catalytic α-Deracemization of Ketones Enabled by Photoredox Deprotonation and Enantioselective Protonation
Chen, Shuming,Gao, Anthony Z.,Ivlev, Sergei I.,Meggers, Eric,Nie, Xin,Ye, Chen-Xi,Zhang, Chenhao
supporting information, p. 13393 - 13400 (2021/09/03)
This study reports the catalytic deracemization of ketones bearing stereocenters in the α-position in a single reaction via deprotonation, followed by enantioselective protonation. The principle of microscopic reversibility, which has previously rendered this strategy elusive, is overcome by a photoredox deprotonation through single electron transfer and subsequent hydrogen atom transfer (HAT). Specifically, the irradiation of racemic pyridylketones in the presence of a single photocatalyst and a tertiary amine provides nonracemic carbonyl compounds with up to 97% enantiomeric excess. The photocatalyst harvests the visible light, induces the redox process, and is responsible for the asymmetric induction, while the amine serves as a single electron donor, HAT reagent, and proton source. This conceptually simple light-driven strategy of coupling a photoredox deprotonation with a stereocontrolled protonation, in conjunction with an enrichment process, serves as a blueprint for other deracemizations of ubiquitous carbonyl compounds.
New process for synthesizing racemic naproxen based on Heck coupling
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Paragraph 0031; 0037; 0038; 0041, (2021/08/06)
The invention discloses a novel process for synthesizing racemic naproxen based on Heck coupling, which comprises the following steps: (1) carrying out Heck coupling reaction on 2-X substituted-6-methoxynaphthalene and crotonamide in an aprotic organic solvent under the action of a palladium catalyst and alkali to generate 3-(6-methoxynaphthyl-2-)-crotonamide; and (2) carrying out Hofmann degradation reaction on the 3-(6-methoxynaphthyl-2-)-crotonamide in an alkaline solution of hypochlorite to generate 2-(6-methoxynaphthyl-2-)-propionaldehyde, directly adding the 2-(6-methoxynaphthyl-2-)-propionaldehyde into chlorite without separation, and conducting oxidizing at room temperature to obtain racemic naproxen. The process provided by the invention does not need to prepare a highly active Grignard reagent, does not need a harsh anhydrous condition, and is relatively high in conversion rate and easy in product purification.
