42399-49-5Relevant academic research and scientific papers
Preparation method of 2-(4-methoxyphenyl)-3-hydroxy-2, 3-dihydro-1, 5-benzothiazepine ketone
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, (2021/01/30)
The invention provides a preparation method of 2-(4-methoxyphenyl)-3-hydroxy-2, 3-dihydro-1, 5-benzothiazepine ketone. The preparation method comprises the following steps: taking o-aminothiophenol and methyl propiolate as raw materials to synthesize an intermediate product 1, carrying out selective epoxidation to obtain an intermediate product 2, reacting the intermediate product 2 with 4-methoxyphenyl anions, carrying out Mitsunobu reaction to obtain an intermediate product 3, and hydrolyzing to obtain the product. In the cyclization process of the intermediate product 1, the tension of Z-structure olefin is small so that the yield is high, subsequent epoxidation is an asymmetric epoxidation reaction, the obtained intermediate product 2 is high in optical purity and high in yield, the intermediate product 2 and 4-methoxyphenyl anions are subjected to SN2 reaction, configuration inversion is carried out in an ortho-position, and the product is obtained. The whole reaction process doesnot need to be split, the total yield of the route is high, and the method is economical.
Selective synthesis method of diltiazem chiral intermediate
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Paragraph 0018; 0042, (2016/10/10)
The invention provides a selective synthesis method of diltiazem chiral intermediate. The method is as below: using anisic aldehyde, chloroacetyl chloride and L-menthol as raw materials; first subjecting chloroacetyl chloride and L-menthol to an esterification reaction to obtain an intermediate 1; then subjecting the intermediate 1 with anisic aldehyde to a Darzens condensation reaction to produce diastereomer intermediates 2 and 3; refining to obtain an optically pure intermediate 3; reacting the intermediate 3 with o-aminothiophenol to obtain an intermediate 4; hydrolyzing the intermediate 4 to obtain an intermediate 5; and cyclizing the intermediate 5 to obtain a product. The invention has the advantages that the ester formed by chloroacetyl chloride and L-menthol is selective in the Darzens condensation reaction with anisic aldehyde to generate the more target product, and solubility difference between the target product and the isomer is used to directly obtain optically pure intermediate, without a complicated resolution process, and the yield is greatly improved. The method substantially increases the utilization rate of the main raw material anisic aldehyde and reduces cost.
Facile ionic liquid-mediated protocol for the regioselective synthesis of 1,5-benzothiazepines
Jain, Renuka,Yadav, Tripti,Kumar, Manoj,Yadav, Ashok K.
experimental part, p. 1889 - 1900 (2011/06/27)
An efficient one-step ionic liquid-mediated green protocol for the regioselective synthesis of (+)=(±)-cis-2-(4-methoxy/benzyloxyphenyl)-3- hydroxy-2,3-dihydro-1,5- benzothiazepin-4-[5H]-ones has been developed from the reaction between substituted 2-aminobenzenethiol and methyl-(±)-trans-3- (4-methoxy/benzyloxy phenyl)glycidate, under nitrogen atmosphere, at 60±2 °C. The reaction has been performed in ionic liquids (viz, 1-butyl-3-methylimidazolium bromide/hexafluorophosphate), and the yields of the 1,5-benzothiazepine derivatives were found to be excellent. The cis-stereoisomer was obtained as the major product along with a trans-isomer as minor product.
Lipase activity of Lecitase Ultra: characterization and applications in enantioselective reactions
Mishra, Mithilesh Kumar,Kumaraguru, Thenkrishnan,Sheelu, Gurrala,Fadnavis, Nitin W.
experimental part, p. 2854 - 2860 (2010/04/05)
The general properties of Lecitase Ultra, a phospholipase manufactured and marketed by Novozymes, Denmark, have been studied after purification by ultrafiltration. The enzyme has a molecular mass of 35 KD, pH-optimum of 8.5, and appears to possess a single active site which exhibits both the lipase and phospholipase activities that increase in the presence of Ca2+ and Mg2+ ions. The enzyme is inhibited by heavy metal ions and surfactants, and does not accept p-nitrophenyl acetate and glycerol triacetate. Substrates, such as glycerol tributyrate and p-nitrophenyl palmitate, esters of N-acetyl-α-amino acids and α-hydroxy acids are readily accepted. Amino acids with aliphatic residues, such as alanine, isoleucine, and methionine, are hydrolyzed with high enantioselectivity for the l-enantiomer (E >100), but amino acids with aromatic residues such as phenylalanine and phenylglycine, and esters of α-hydroxy acids are hydrolyzed with low enantioselectivity (E = 1-5). Immobilization of the enzyme in a gelatin matrix (gelozyme) leads to a marginal improvement in the enantioselectivity for these substrates. However, a dramatic improvement in enantioselectivity is observed for ethyl 2-hydroxy-4-oxo-4-phenylbutyrate (E value increases from 4.5 to 19.5 with S-selectivity). Similarly, glycidate esters, such as ethyl trans-(±)-3-phenyl glycidate and methyl trans-(±)-3-(4-methoxyphenyl) glycidate, are selectively hydrolyzed with a remarkable selectivity towards the (2S,3R)-enantiomer providing unreacted (2R,3S)-glycidate esters (ee >99%, conversion 52-55%) by the immobilized enzyme.
Novel protocol for the asymmetric synthesis of 3-hydroxy-2-(4-methoxyphenyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one via bakers' yeast reduction
Komiyama, Takuzo,Takaguchi, Yutaka,Tsuboi, Sadao
, p. 147 - 151 (2007/10/03)
A novel protocol for the asymmetric synthesis of 3-hydroxy-2-(4-methoxyphenyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one is reported. Darzens condensation reactions of anisaldehyde with dichloroacetates, followed substitution reaction of sodium o-nitrophenylthiolate and bakers' yeast reduction furnished 2-hydroxy-3-(4-methoxyphenyl)-3-(2-nitrophenylsulfanyl)-propionates. Further reduction of a nitro group and cyclization gave the title compound.
Process for preparing diltiazem using a heterogeneous trifunctional catalyst
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Page 3, (2008/06/13)
The present invention comprises a simplified synthesis of (+)-diltiazem through IE-PdOsW wherein IE is ion-exchanger, catalyzed three-component coupling reaction and Fe3+-exchanged clay catalyzed ring opening of sulfite with 2-aminothiophenol followed by cyclization as key steps.
PROCESS FOR PREPARING DILTIAZEM USING A HETEROGENEOUS TRIFUNCTIONAL CATALYST
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Page 3, (2008/06/13)
The present invention comprises a simplified synthesis of (+)-diltiazem through IE-PdOsW wherein IE is ion-exchanger, catalyzed three-component coupling reaction and Fe3+-exchanged clay catalyzed ring opening of sulfite with 2-aminothiophenol followed by cyclization as key steps.
A trifunctional catalyst for one-pot synthesis of chiral diols via heck coupling-N-oxidation-asymmetric dihydroxylation: Application for the synthesis of diltiazem and taxol side chain
Choudary, Boyapati M.,Chowdari, Naidu S.,Madhi, Sateesh,Kantam, Mannepalli L.
, p. 1736 - 1746 (2007/10/03)
A heterogeneous bifunctional catalyst composed of OsO42--WO42- and a trifunctional catalyst comprising PdCl42--OsO42-- WO42-, designed and prepared by an ion-exchange technique using layered double hydroxides (LDH) as an ion-exchanger and their homogeneous bifunctional analogue, K2OsO4-Na2WO4 and trifunctional analogue, Na2PdCl4-K2OsO4-K2 OSO4-NNa2WO4, devised for the first time are evaluated for the synthesis of chiral vicinal diols. These bifunctional and trifunctional catalysts perform asymmetric dihydroxylation-N-oxidation and Heck-asymmetric dihydroxylation-N-oxidation, respectively, in the presence of Sharpless chiral ligand, (DHQD)2PHAL in a single pot using H2O2 as a terminal oxidant to provide N-methylmorpholine oxide (NMO) in situ by the oxidation of N-methylmorpholine (NMM). The heterogeneous bifunctional catalyst supported on LDH (LDH-OsW) displays superior activity to afford diols with higher yields over the other heterogeneous catalysts developed by the ion exchange on quaternary ammonium salts covalently bound to resin (resin-OsW) and silica (silica-OsW) or homogeneous catalysts in the achiral dihydroxylation reactions. The LDH-OsW and its homogeneous analogue are found to be very efficient in performing a simultaneous asymmetric dihydroxylation (AD)-N-oxidation of a wide and varied range of aromatic, cyclic, and mono, di-, and trisubstituted olefins to obtain chiral vicinal diols with higher yields and ee's using H2O2. Further, the use of OsO42--WO42-- WO42- catalysts as such or in the supported form offers a simplified procedure for catalyst recycling, which shows consistent activity for a number of cycles. In this process, OsVI is recycled to OsVIII by a coupled electron transfer-mediator (ETM) system based on NMO-WO42- using H2O2, leading to a mild and selective electron transfer. The one-pot biomimic synthesis of chiral diols is mediated by a recyclable trifunctional heterogeneous catalyst (LDH-PdOsW) consisting of active palladium, tungsten, and osmium species embedded in a single matrix. This protocol, which provides prochiral olefins and NMO in situ by Heck coupling and N-oxidation of NMM, respectively, required for the AD, unfolds a low cost process. We extended the present method to the one-pot synthesis of trisubstituted chiral vicinal diols with moderate to excellent ee's by AD of trisubstituted olefins that are obtained by in situ Heck arylation of disubstituted olefins. The heterogeneous trifunctional catalysts offers chiral diols with unprecedented ee's and excellent yields in the AD of prochiral cinnamates, which are obtained in situ from acrylates and halobenzenes for the first time. The new variants such as LDH support and Et3N·HX inherently composed in the heterogeneous multicomponent system and slow addition of H202 facilitates the hydrolysis of osmium monogylcolate ester to subdue the formation of bisglycolate ester to achieve higher ee's. Without resorting to recrystallization, the chiral diols of cinnamates thus synthesized with 99% ee's and devoid of osmium contamination are directly put to use in the synthesis of diltiazem and Taxol side chain with an overall improved yield to demonstrate the synthetic utility of the trifunctional heterogeneous catalyst. The high binding ability of the heterogeneous osmium catalyst enables the use of equimolar ratio of ligand to osmium to give excellent ee's in AD in contrast to the homogeneous osmium system in which the excess molar quantities of the expensive chiral ligand to osmium are invariably used. Further, the XRD, FT-IR, UV-vis DRS, and XPS studies indicate the retention of the coordination geometries of the specific divalent anions anchored to LDH matrix in their monomeric form during the ion exchange and after the reaction.
Stereoselective Synthesis of Diltiazem via Dynamic Kinetic Resolution
Mordant, Celine,De Andrade, Cristina Cano,Touati, Ridha,Ratovelomanana-Vidal, Virginie,Hassine, Bechir Ben,Genet, Jean-Pierre
, p. 2405 - 2409 (2007/10/03)
An efficient synthesis of diltiazem has been developed using dynamic kinetic resolution (DKR) as a key step. The methyl (2S,3S)-2-chloro-3-hydroxy-3- (4-methoxyphenyl)propionate was synthesized from a racemic mixture of α-chloro-β-keto ester, with high anti diastereoselectivity (92%) and enantioselectivity (95%), based on an asymmetric hydrogenation reaction with a chiral ruthenium(II) catalyst, simply prepared by mixing Ru(cod)(2-methylallyl) 2 with the atropisomeric ligand (S)-MeO-BIPHEP. By treatment of this α-chloro-β-hydroxy ester with a base, the corresponding trans methyl glycidate, a key intermediate of diltiazem, was easily obtained.
Process for the preparation of a benzothiazepine
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, (2008/06/13)
Process for the preparation of a 1,5-benzothiazepine derivative, or a salt thereof, of formula 1 STR1 where R1 represents H, an alkyl group or an alkoxy group and R2 represents H or a halogen, in which process a propanoic acid derivative of formula 2 STR2 where R1 and R2 are as defined above and R3 represents H or an alkyl group is subjected to an intramolecular cyclisation reaction in a non-halogenated solvent in the presence of a carboxylic acid. Preferably, R2 is H and R1 is OCH3. Trichloroacetic acid is preferably used as α-chlorinated acid. The benzothiazepine obtained on cyclisation can be subjected to an alkylation reaction and/or an acylation reaction to obtain known pharmaceutical products, in particular diltiazem.
