- Preparation method of nepafenac
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The invention discloses a preparation method of nepafenac. The method comprises the following steps: 1, synthesizing 2-(methylthio) acetamide; 2, synthesizing alpha-methylthio (2-amino-3-benzoyl) phenylacetamide; 3, synthesizing the nepafenac. Compared with the prior art, the preparation method of the nepafenac has the advantages that raw materials are easy to buy, excessive chlorinated impurities of a side reaction are easily purified, the less energy is consumed by increasing reaction temperature, and the final product does not need to be subjected to octadecyl silane (ODS) reverse phase rapid chromatography.
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Paragraph 0035; 0043; 0050; 0051
(2017/09/01)
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- Process For Preparing A Benzoylbenzeneacetamide Derivative
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Disclosed is a process for preparing anti-inflammatory compound nepafenac comprising preparing a compound of formula (V) wherein a N-halosuccinimide is used as the halogenating agent, followed by desulfurization using Raney Nickel. Also disclosed is a polymorphic form B of 2-amino-3-benzoyl-α-(methylthio)-benzeneacetamide (i.e., a compound of formula (V) wherein R is methyl
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Page/Page column 6-7
(2009/12/27)
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- Enzymatic nitrile hydrolysis catalyzed by nitrilase ZmNIT2 from maize. An unprecedented β-hydroxy functionality enhanced amide formation
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To explore the synthetic potential of nitrilase ZmNIT2 from maize, the substrate specificity of this nitrilase was studied with a diverse collection of nitriles. The nitrilase ZmNIT2 showed high activity for all the tested nitriles except benzonitrile, producing both acids and amides. For the hydrolysis of aliphatic, aromatic nitriles, phenylacetonitrile derivatives and dinitriles, carboxylic acids were the major products. Unexpectedly, amides were found to be the major products in nitrilase ZmNIT2-catalyzed hydrolysis of β-hydroxy nitriles. The hydrogen bonding between the hydroxyl group and nitrogen in the enzyme-substrate complex intermediates that disfavors the loss of ammonia and formation of acyl-enzyme intermediate, which was further hydrolyzed to acid, was proposed to be responsible for the unprecedented β-hydroxy functionality assisted high yield of amide formation.
- Mukherjee, Chandrani,Zhu, Dunming,Biehl, Edward R.,Parmar, Rajiv R.,Hua, Ling
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p. 6150 - 6154
(2007/10/03)
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- Mass Spectrometry of 2-Alkylthio-2-methylpropanoic Acids and Their Esters and Amides. Structural and Steric Effects on the McLafferty Rearrangement
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The electron ionization mass spectra (MS) of S-methylated derivatives of N-(2-mercapto-2-methylpropanoyl)-L-cysteine and 2-alkylthio-2-methylpropanoic acids, as well as their esters and amides, were examined.Use of the deuterium labeling technique and accurate mass measurement supported the proposed fragmentation pathways.Extensive loss of CH2S from a molecular ion by the McLafferty rearrangementof a primary hydrogen is important in the MS of S-methyl compounds of amide derivatives.It was demonstrated that the intensity of the rearrangement ion decreases in the order of amide, ester, and acid, and in the case if amides the reaarangement is suppressed by the nonbonded interaction between methyl groups on the α carbon and the amide nitrogen.Keywords-N-(2-mercapto-2-methylpropanoyl)-L-cysteine; 2-alkylthio-2-methylpropanoic acid and methyl ester; 2-alkylthio-2-methylpropanamide; electron impact mass spectrometry; McLafferty rearrangement; steric interaction
- Mori, Yuji,Fujiwara, Shigeru,Miyachi, Toshiko,Kitanishi, Hiroyuki,Oya, Masayuki,et al.
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p. 1505 - 1517
(2007/10/02)
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