Browsing College of Science by Author "McArdle, Patrick"
Now showing items 1-20 of 34
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Allylic azide rearrangement in tandem with Huisgen cycloaddition for stereoselective annulation: synthesis of C-Glycosyl iminosugars
Moynihan, Lorna; Chadda, Rekha; McArdle, Patrick; Murphy, Paul V. (American Chemical Society, 2015-12-09)Allylic azide rearrangement is used. in,tandem with. intramolecular azide-alkene cycloaddition to give a triazoline that when subsequently decomposed in the presence of a nucleophile gives piperidines. The tandem reaction ... -
Allylic azide rearrangement in tandem with intramolecular Huisgen cycloaddition for iminosugar and glycomimetic synthesis. Functionalized piperidine, pyrrolidine and pyrrolotriazoles from D-mannose
Chadda, Rekha; McArdle, Patrick; Murphy, Paul V. (Thieme Publishing, 2017-04-20)Intramolecular Huisgen azide-alkene cycloaddition reaction of 7-azido-hepta-1,5-diene-3,4-diols, prepared from methyl α-d-mannopyranoside, were carried out. Allylic azide rearrangement to secondary azides occurred ... -
Application of ball milling for highly selective mechanochemical polymorph transformations
Kamali, Naghmeh; Gniado, Katarzyna; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2018-06-07)Milling is an important secondary processing technique in the manufacture of pharmaceuticals, primarily used as a particle size reduction process. p-Aminobenzoic acid (PABA), m-aminobenzoic acid (MABA), o-aminobenzoic acid ... -
Building blocks from monosaccharides for synthesis of scaffolds, including macrocycles. Application of allylic azide rearrangement, azide-alkyne cycloaddition and ring closing metathesis
Fox, Karen A.; Chadda, Rekha; Cardona, Francisco; Barron, Stephen; McArdle, Patrick; Murphy, Paul V. (Elsevier, 2020-09-18)Synthesis of compounds with characteristics of natural products are required to increase the diversity and biological relevance of compounds for screening. These include new frameworks/scaffolds, with multiple stereogenic ... -
Cocrystal forms of the BCS class IV drug sulfamethoxazole
Alsubaie, Moneerh; Aljohani, Marwah; Erxleben, Andrea; McArdle, Patrick (American Chemical Society, 2018-05-23)Sulfamethoxazole, smz, is an antibiotic that is classified as a Biopharmaceutics Classification System (BCS) class IV, low solubility and low permeability drug. Cocrystal formation has been examined in an attempt to improve ... -
A comprehensive cocrystal screening study of chlorothiazide
Aljohani, Marwah; Pallipurath, Anuradha R.; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2017-09-01)Cocrystal formation of chlorothiazide (ctz) was screened with a variety of coformers with carboxyl, amide, hydroxyl, sulfonamide, pyridine, amidine, and amine functional groups. New cocrystals with acetamide (aca), benzamide ... -
A comprehensive spectroscopic study of the polymorphs of diflunisal and their phase transformations
Pallipurath, Anuradha R.; Civati, Francesco; Sibik, Juraj; Crowley, Clare; Zeitler, J. Axel; McArdle, Patrick; Erxleben, Andrea (Elsevier, 2017-06-08)Understanding phase transitions in pharmaceutical materials is of vital importance for drug manufacturing, processing and storage. In this paper we have carried out comprehensive high-resolution spectroscopic studies on ... -
Conversion of gel-forming crystal needles to easily processable more equant crystals Using high-shear ultralow attrition agitation: accelerated Ostwald ripening without crystal attrition
Civati, Francesco; Erxleben, Andrea; Kellehan, Seamus; McArdle, Patrick (American Chemical Society, 2019-02-01)We demonstrate the first examples of the transformation of gel-forming crystal needles into easily processable more equant crystals by accelerated Ostwald ripening without detectable crystal attrition. Using high solution ... -
Crystallization of organic salts from the gas phase: When does proton transfer take place?
O’Malley, Ciarán; Erxleben, Andrea; McArdle, Patrick; Simmie, John M. (American Chemical Society, 2020-12-13)Salt formation with proton transfer is observed in crystals grown by cosublimation of the salt coformers. Diflunisal salts were obtained with 4-[3-(pyridin-4-yl)propyl]pyridine, piperazine, and 4-dimethylaminopyridine. ... -
Cytotoxicity and antimicrobial activity of triorganotin(IV) complexes of phenylcyanamide prepared by sonochemical synthesis
Tabrizi, Leila; McArdle, Patrick; Erxleben, Andrea; Chiniforoshan, Hossein (Elsevier, 2015-09-25)This article describes the synthesis and characterization of novel triorganotin(IV) complexes and their potential medicinal applications. Triorganotin(IV) complexes with formulas [(SnMe3)(2)(mu-bp)(H2O)(2)], 1, and ... -
Dual-drug amorphous formulation of gliclazide
Aljohani, Marwah; McArdle, Patrick; Erxleben, Andrea (Taylor and Francis, 2021-02-01)Amorphization is a well-established strategy to enhance the dissolution properties of poorly water-soluble drugs. However, the amorphous state is inherently unstable toward recrystallization. Coamorphous systems of a drug ... -
Effects of ball-milling and cryomilling on sulfamerazine polymorphs: A quantitative study
MacFhionnghaile, Pól; Hu, Yun; Gniado, Katarzyna; Curran, Sinead; McArdle, Patrick; Erxleben, Andrea (Elsevier, 2014-04-11)The effects of ball-milling and cryomilling on sulfamerazine forms I and II (SMZ FI, FII) were investigated using X-ray powder diffraction, infrared and near-infrared (NIR) spectroscopy. Cryomilling resulted in a complete ... -
A F-bridged Mn(II) molecular square
Meally, Sean T.; McArdle, Patrick; Ryder, Alan G.; Jones, Leigh F. (RSC, 2009-10-08)We report on a tetranuclear Mn(II) complex possessing a F-bridged molecular square topology directed by 1,10-phenanthroline ligands. -
A family of double-bowl pseudo metallocalix[6]arene discs
Meally, Sean T.; McDonald, Cecelia; Dunne, Peter W.; McArdle, Patrick; Jones, Leigh F. (RSC, 2010-03-10)We report the synthesis and magnetic characterisation of a series of planar [M7] (M = NiII, ZnII) disc complexes [Ni7(OH)6(L1)6](NO3)2 (1), [Ni7(OH)6(L1)6](NO3)2·2MeOH (2), [Ni7(OH)6(L1)6](NO3)2·3MeNO2 (3), [Ni7(OH)6(L2) ... -
Formation, physical stability, and quantification of process-induced disorder in cryomilled samples of a model polymorphic drug
Hu, Yun; MacFhionnghaile, Pól; Caron, Vincent; Tajber, Lidia; Healy, Anne Marie; Erxleben, Andrea; McArdle, Patrick (Elsevier, 2012-10-09)The formation and physical stability of amorphous sulfathiazole obtained from polymorphic forms I and III by cryomilling was investigated by X-ray powder diffraction (XRPD) and near-infrared (NIR) spectroscopy. Principal ... -
Hydrogen bonding networks and solid-state conversions in benzamidinium salts
Kamali, Naghmeh; Aljohani, Marwah; McArdle, Patrick; Erxleben, Andrea (2015-07-14)Ten benzamidinium salts of carboxylic acids, amides, and sulfonamides have been crystallized from solution. Single-crystal X-ray analyses revealed various hydrogen bonding motifs which ate discussed in terms of supramolecular ... -
Influence of excipients on cocrystal stability and formation
Aljohani, Marwah; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2020-05-26)Cocrystal formation is widely used to modify and optimize the physicochemical properties of an active pharmaceutical ingredient (API). However, the stability of cocrystals toward formulation with excipients is little ... -
Investigation of the formation of drug-drug cocrystals and coamorphous systems of the antidiabetic drug gliclazide
Aljohani, Marwah; MacFhionnghaile, Pól; McArdle, Patrick; Erxleben, Andrea (Elsevier, 2019-02-23)The antidiabetic drug gliclazide (GLZ) has a slow absorption rate and a low bioavailability due to its poor solubility. GLZ is often prescribed along with an antihypertensive, as many diabetic patients have coexistent ... -
Manipulating cocrystal size and morphology using a combination of temperature cycling and additives
Civati, Francesco; Svoboda, Vaclav; Urwin, Stephanie Jane; McArdle, Patrick; Erxleben, Andrea; Croker, D.; ter Horst, Joop (American Chemical Society, 2020-11-20)A cooling crystallization of benzoic acid and isonicotinamide in ethanol yields the 1:1 cocrystal with an extreme needle-like morphology with an initial mean aspect ratio of ∼10 and a size of ∼64 μm. We demonstrate that ... -
The natural bile acid surfactant sodium taurocholate (NaTC) as a coformer in coamorphous systems: Enhanced physical stability and dissolution behavior of coamorphous drug-NaTc systems
Gniado, Katarzyna; MacFhionnghaile, Pól; McArdle, Patrick; Erxleben, Andrea (Elsevier, 2018-10-28)The amorphization of 18 different drugs on milling with one mole equivalent sodium taurocholate (NaTC) was investigated. In all cases the X-ray powder pattern showed an amorphous halo after milling at room temperature or ...