La presente invention concerne un nouveau procede de preparation de droxidopa, un precurseur synt... more La presente invention concerne un nouveau procede de preparation de droxidopa, un precurseur synthetique d'acide amine de norepinephrine. Le procede est un procede stereoselectif de preparation de droxidopa qui fait appel a l'induction asymetrique et evite ainsi le procede de synthese impliquant la resolution chirale. La presente invention decrit egalement de nouveaux intermediaires de formule III, formule V et formule VI.
Pharmaceutical Development, AstraZeneca India Pvt. Ltd., Bellary Road, Bangalore-560 024, India C... more Pharmaceutical Development, AstraZeneca India Pvt. Ltd., Bellary Road, Bangalore-560 024, India Chemistry Division, School of Advanced Sciences, VIT University, Vellore-632 014, Tamilnadu, India E-mail : drprbhagat111@gmail.com A mild and efficient method for carbon-oxygen bond formation for the synthesis of aryl ethers has been demonstrated using stoichiometric amount of alcohol and tetrabutylammonium hydroxide (TBAH). The protocol is free from the metal alkoxides, inorganic bases or metal catalysts. This methodology has been applied for synthesis of paracetamol and nimesulide intermediates.
A novel 1-glycyl-3-methyl imidazolium chloride–palladium (II) complex [[Gmim]Cl–Pd (II)] was foun... more A novel 1-glycyl-3-methyl imidazolium chloride–palladium (II) complex [[Gmim]Cl–Pd (II)] was found to be a heterogeneous catalyst for an efficient Heck reac.
Abstract A novel, effective asymmetric 1-glycyl-3-methyl imidazolium chloride–iron(III) [[Gmim]Cl... more Abstract A novel, effective asymmetric 1-glycyl-3-methyl imidazolium chloride–iron(III) [[Gmim]Cl–Fe(III)] complex was synthesized and studied as organocatalyst in asymmetric aldol addition under solvent free condition at 25 °C. The hydrophobic group of amino acid favors reagent diffusion toward the chloroglycine moiety increasing the catalytic activity of supported iron complex. This method contains simplified product isolation and catalyst recycling, affording substituted aromatic aldehydes imparting high yield of aldol with excellent stereo-selectivity. This recyclable heterogeneous catalyst provides a simple strategy for the generation of a variety of new C C bonds under environmentally benign condition.
ABSTRACT A simple and practical method of recycling homogeneous catalysts in the Suzuki reaction ... more ABSTRACT A simple and practical method of recycling homogeneous catalysts in the Suzuki reaction using appropriate work up conditions is reported here. The commonly used and commercially available homogeneous catalysts 1 (Pd-100) dichlorobis(tri-phenylphosphine)palladium(II), 2 (Pd-106) dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II)-dichloromethane adduct, and 3 (Pd-118) 1,1′-bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II) selected for our study and were recycled successfully for three times using simple acidic and basic work up conditions depending on the presence of amino or carboxylic acid functional group in the product.
ABSTRACT The development of a convenient, safe and scalable process for AZD8329 manufacturing is ... more ABSTRACT The development of a convenient, safe and scalable process for AZD8329 manufacturing is reported here. Synthesis was achieved in a two-step telescopic process with an excellent overall yield of 75%. In the first step enamine (6) was synthesized with 90% yield through three chemical transformations. In the next step AZD8329 was synthesized from the reactions of 6 and 4-hydrazinobenzoic acid hydrochloride 7 through two chemical transformations. The process is very efficient and economical, and AZD8329 was manufactured in multikilogram scale. A greener approach is demonstrated through usage of a minimum number of solvents and energy and with process mass intensity (PMI) <60 in the manufacturing process.
La presente invention concerne un nouveau procede de preparation de droxidopa, un precurseur synt... more La presente invention concerne un nouveau procede de preparation de droxidopa, un precurseur synthetique d'acide amine de norepinephrine. Le procede est un procede stereoselectif de preparation de droxidopa qui fait appel a l'induction asymetrique et evite ainsi le procede de synthese impliquant la resolution chirale. La presente invention decrit egalement de nouveaux intermediaires de formule III, formule V et formule VI.
Pharmaceutical Development, AstraZeneca India Pvt. Ltd., Bellary Road, Bangalore-560 024, India C... more Pharmaceutical Development, AstraZeneca India Pvt. Ltd., Bellary Road, Bangalore-560 024, India Chemistry Division, School of Advanced Sciences, VIT University, Vellore-632 014, Tamilnadu, India E-mail : drprbhagat111@gmail.com A mild and efficient method for carbon-oxygen bond formation for the synthesis of aryl ethers has been demonstrated using stoichiometric amount of alcohol and tetrabutylammonium hydroxide (TBAH). The protocol is free from the metal alkoxides, inorganic bases or metal catalysts. This methodology has been applied for synthesis of paracetamol and nimesulide intermediates.
A novel 1-glycyl-3-methyl imidazolium chloride–palladium (II) complex [[Gmim]Cl–Pd (II)] was foun... more A novel 1-glycyl-3-methyl imidazolium chloride–palladium (II) complex [[Gmim]Cl–Pd (II)] was found to be a heterogeneous catalyst for an efficient Heck reac.
Abstract A novel, effective asymmetric 1-glycyl-3-methyl imidazolium chloride–iron(III) [[Gmim]Cl... more Abstract A novel, effective asymmetric 1-glycyl-3-methyl imidazolium chloride–iron(III) [[Gmim]Cl–Fe(III)] complex was synthesized and studied as organocatalyst in asymmetric aldol addition under solvent free condition at 25 °C. The hydrophobic group of amino acid favors reagent diffusion toward the chloroglycine moiety increasing the catalytic activity of supported iron complex. This method contains simplified product isolation and catalyst recycling, affording substituted aromatic aldehydes imparting high yield of aldol with excellent stereo-selectivity. This recyclable heterogeneous catalyst provides a simple strategy for the generation of a variety of new C C bonds under environmentally benign condition.
ABSTRACT A simple and practical method of recycling homogeneous catalysts in the Suzuki reaction ... more ABSTRACT A simple and practical method of recycling homogeneous catalysts in the Suzuki reaction using appropriate work up conditions is reported here. The commonly used and commercially available homogeneous catalysts 1 (Pd-100) dichlorobis(tri-phenylphosphine)palladium(II), 2 (Pd-106) dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II)-dichloromethane adduct, and 3 (Pd-118) 1,1′-bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II) selected for our study and were recycled successfully for three times using simple acidic and basic work up conditions depending on the presence of amino or carboxylic acid functional group in the product.
ABSTRACT The development of a convenient, safe and scalable process for AZD8329 manufacturing is ... more ABSTRACT The development of a convenient, safe and scalable process for AZD8329 manufacturing is reported here. Synthesis was achieved in a two-step telescopic process with an excellent overall yield of 75%. In the first step enamine (6) was synthesized with 90% yield through three chemical transformations. In the next step AZD8329 was synthesized from the reactions of 6 and 4-hydrazinobenzoic acid hydrochloride 7 through two chemical transformations. The process is very efficient and economical, and AZD8329 was manufactured in multikilogram scale. A greener approach is demonstrated through usage of a minimum number of solvents and energy and with process mass intensity (PMI) <60 in the manufacturing process.
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Papers by Suresh Kumar Sythana