Shivaprakash S.,Vittal Mallya Scientific Research Foundation VMSRF |
Reddy G.C.,Vittal Mallya Scientific Research Foundation VMSRF |
Jasinski J.P.,Keene State College |
Millikan S.P.,Keene State College |
And 2 more authors.
Acta Crystallographica Section C: Structural Chemistry | Year: 2015
Triphenyl(2,4,5-trimethoxybenzyl)phosphonium chloride is formed in solvent-free form by the reaction under anhydrous conditions between triphenylphosphane and 2,4,5-trimethoxybenzyl chloride, but when it is crystallized from a mixture of ethyl acetate and chloroform in the presence of air it forms a stoichiometric monohydrate, C28H28O3P+·Cl-·H2O, (I). The reactions between the anhydrous phosphonium salt and alkoxy-substituted benzaldehydes, using Wittig reactions in the presence of potassium tert-butoxide, provide a series of multiply substituted stilbenes, most of which were assigned the Z configuration on the basis of their NMR spectra. However, no such deduction could be made for the symmetrically substituted (Z)-2,2′,4,4′,5,5′-hexamethoxystilbene, C20H24O6, (II). Compound (II) does in fact have the Z configuration and the molecular geometry provides evidence for steric congestion around the central double bond; in particular, the central alkene fragment is nonplanar, with a C-C=C-C torsion angle of 7.8(4)°. In hydrated salt (I), the chloride anions and water molecules are linked by O-H⋯Cl hydrogen bonds to form C21(4) chains; each cation is linked by C-H⋯O hydrogen bonds to two different chains, so forming a sheet structure. There are no direction-specific intermolecular interactions in the structure of (II). © 2015 International Union of Crystallography.
Chandrashekara K.A.,Vittal Mallya Scientific Research Foundation VMSRF |
Udupi A.,Vittal Mallya Scientific Research Foundation VMSRF |
Reddy C.G.,Vittal Mallya Scientific Research Foundation VMSRF
Journal of Chromatographic Science | Year: 2014
A simple and rapid reverse-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous separation and estimation of gefitinib (an anti-cancer drug) and its process-related impurities. Five process-related impurities of gefitinib were separated on an Inertsil ODS-3V column (250 3 4.6 mm i.d.; particle size 5 mm) using 130 mM ammonium acetate and acetonitrile (63:37, v/v) as mobile phase (pH 5.0) with a photodiode array (PDA) detector. The correlation coefficients for gefitinib and its processrelated impurities were in the range of 0.9991-0.9994 with limit of detection and limit of quantification in the range of 0.012-0.033 and 0.04-0.10 μg/mL, respectively. The recovery values were in the range of 98.26-99.90% for gefitinib and 95.99-100.55% for processrelated impurities, while precision values were less than 3%. The method was found to be specific, precise and reliable for the determination of gefitinib and its impurities in gefitinib bulk drug. © The Author .
Karunakara A.C.,Vittal Mallya Scientific Research Foundation VMSRF |
Aparna U.,Vittal Mallya Scientific Research Foundation VMSRF |
Kush A.,Vittal Mallya Scientific Research Foundation VMSRF |
Chandrasekara Reddy G.,Vittal Mallya Scientific Research Foundation VMSRF
Journal of Liquid Chromatography and Related Technologies | Year: 2013
A simple and rapid reverse-phase high-performance liquid chromatographic (RP-HPLC) method for the estimation of intermediates formed during the synthesis of anti-cancer drug erlotinib via quinazoline-thione route has been developed. The intermediates formed during the 7-step synthesis of erlotinib have been separated on a Inerstsil ODS-3 V (C18) column with isocratic elution using 1% ammonium acetate and acetonitrile (55:45 v/v) as mobile phase, with flow rate of 1 mL/min and detected at 254 nm using Photo Diode Array (PDA). The developed method was validated for accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ) and ruggedness. The correlation coefficients for calibration curves of intermediates were in the range of 0.995-0.999. The proposed reverse-phase HPLC method was successfully applied for the estimation of intermediates/impurities present in erlotinib bulk drug; the recoveries of intermediates were in the range of 96.83-100.96% and precision values were less than 3%. The method was found to be specific, precise, and reliable for the determination of intermediates and synthetic impurities in erlotinib bulk drug. © 2013 Taylor and Francis Group, LLC.