Bernardi L.,University of Bologna |
Fochi M.,University of Bologna |
Carbone R.,University of Bologna |
Martinelli A.,University of Bologna |
And 6 more authors.
Chemistry - A European Journal | Year: 2015
In the context of a programme directed at the manufacture of telaprevir, eight possible approaches to its bicyclic α-amino acid core, based on organocatalytic enantioselective conjugate additions to cyclopent-1-enecarbaldehyde, were identified and preliminarily explored. Four reactions, delivering advanced intermediates en route to the target amino acid, were selected for a thorough optimisation. Three of this reactions involved iminium ion catalysis with a prolinol catalyst (addition of nitromethane, nitroacetate and acetamidomalonate) and one was based on a Cinchona-derived phase-transfer catalyst (addition of glycine imines). A careful choice of additives allowed lowering of the catalyst loading to 0.5 mol % in some cases. The preparation of intermediates that would give access to the core of telaprevir in good yields and enantioselectivities by exploiting readily available substrates and catalysts, highlights the potential of organocatalytic technology for a cost-effective preparation of pharmaceuticals. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Thakur P.,Maithili Life science Pvt. Ltd. |
Kumaraswamy B.,Maithili Life science Pvt. Ltd. |
Raji Reddy G.,Maithili Life science Pvt. Ltd. |
Bandichhor R.,Dr. Reddys Laboratories Ltd. Bachupally |
Mukkanti K.,Jawaharlal Nehru Technological University Anantapur
Tetrahedron Letters | Year: 2012
The first stereoselective total synthesis of polyacetylene panaxjapyne C is described. The key reactions include regioselective opening of the epoxide and Cadiot-Chodkiewicz cross-coupling reactions. l-Ascorbic acid was used as a chiral pool material for the construction of the both terminal acetylenes. © 2012 Elsevier Ltd. All rights reserved.
Reddy P.,Dr. Reddys Laboratories Ltd. Bachupally |
Reddy P.,iversity |
Babu K.,iversity |
Kumar N.,Dr. Reddys Laboratories Ltd. Bachupally
Acta Chromatographica | Year: 2014
A stability-indicating gradient reverse-phase liquid chromatographic method was developed for the quantitative determination of process-related impurities and forced degradation products of oxcarbazepine in pharmaceutical formulation. The method was developed by using Inertsil cyano (250 × 4.6 mm) 5 μm column with mobile phase containing a gradient mixture of solvent A (0.01 M sodium dihydrogen phosphate, pH adjusted to 2.7 with orthophosphoric acid and acetonitrile in the ratio of 80:20 v/v) and B (50:40:10 v/v/v mixture of acetonitrile, water, and methanol). The flow rate of mobile phase was 1.0 mL min-1. Column temperature was maintained at 25°C and detection wavelength at 220 nm. Developed reverse-phase high-performance liquid chromatography (RP-HPLC) method can adequately separate and quantitate five impurities of oxcarbazepine, namely imp-A, imp-B, imp-C, imp-D, and imp-E. Oxcarbazepine was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal, and photolytic degradation. Oxcarbazepine was found to degrade significantly in acid, base, and oxidative stress conditions. The degradation products were well resolved from oxcarbazepine and its impurities. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision, and robustness.
Geetha M.,Dr. Reddys Laboratories Ltd. Bachupally |
Venkat Rao P.,Dr. Reddys Laboratories Ltd. Bachupally |
Sait S.,Dr. Reddys Laboratories Ltd. Bachupally |
Palvai S.R.,Dr. Reddys Laboratories Ltd. Bachupally
Oriental Journal of Chemistry | Year: 2013
A novel, sensitive and selective isocratic reverse phase high performance liquid chromatographic method was developed and validated for quantitative determination of eberconazole, mometasone furoate and methylparaben in ointment formulations. The chromatographic separation was achieved on Waters Symmetry C-18 (250 × 4.6mm, 5μ) column by using mobile phase containing a mixture of solvent A (0.5g of 1-Hexane sulphonic acid sodium salt and 0.5mL of triethyl amine in 500mL of Milli-Q water, pH 6.0) and B (acetonitrile) in the ratio of 20:80 at flow rate of 1.0 mL/min. Column temperature was maintained at 30°C and detection was carried out at a wavelength of 240 nm. The developed method was validated with respect to specificity, linearity, precision, accuracy and robustness. Forced degradation studies were performed on the placebo and drug product, all degradation products were well separated from eberconazole, mometasone furoate and methylparaben.