Browsing School of Chemistry by Author "McArdle, Patrick"
Now showing items 1-20 of 29
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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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
One-pot hydrogen peroxide and hydrohalic acid induced ring closure and selective aromatic halogenation to give new ring-fused benzimidazoles
Gurry, Michael; Sweeney, Martin; McArdle, Patrick; Aldabbagh, Fawaz (American Chemical Society, 2015-05-19)A new series of selectively dichlorinated and dibrominated five- to eight-membered-ring [1,2-a]-fused benzimidazoles and [1,4]oxazino[4,3-a]benzimidazoles are synthesized in mostly high yields of >80% using the reaction ... -
Planar [Ni-7] discs as double-bowl, pseudo metallacalix[6]arene host cavities
Meally, Sean T.; Dunne, Peter W.; McArdle, Patrick; Jones, Leigh F. (RSC, 2010-09-19)We report three heptanuclear[Ni-7] complexes with planar disc-like cores, akin to double-bowl metallocalix[6]arenes, which form molecular H-bonded host cavities. -
Solid-state transformations of sulfathiazole polymorphs: The effects of milling and humidity
Hu, Yun; Erxleben, Andrea; Hodnett, Kieran; Li, Boyan; McArdle, Patrick; Rasmuson, Åke C.; Ryder, Alan G. (American Chemical Society, 2013-07-11)The effect of milling on the transitions of sulfathiazole polymorphs in the absence and presence of solvent and excipients was monitored by X-ray powder diffraction (XRPD), attenuated total reflectance infrared (ATR-IR), ... -
Spontaneous solid-state cocrystallization of caffeine and urea
MacFhionnghaile, Pól; Crowley, Clare M.; McArdle, Patrick; Erxleben, Andrea (American Chemical Society, 2020-01-09)The cocrystallization of caffeine and urea was monitored and analyzed using infrared spectroscopy, Raman microscopy, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. The caffeine-urea ...