02858nas a2200217   4500008004100000022001400041245009400055210006900149260007100218300001400289490000700303520205200310100001902362700002402381700002502405700002302430700001902453700002502472700002402497856011902521       2015                        eng d  a1528-748300aFurosemide cocrystals with pyridines: an interesting case of color cocrystal polymorphism0 aFurosemide cocrystals with pyridines an interesting case of colo  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC  a5858-58720 v153 a<p>Furosemide (FS), a loop diuretic drug commonly used for the treatment of hypertension and edema, exhibited color cocrystal polymorphism with coformer 4,4'-bipyridine (4BPY) in the stoichiometry 2:1, albeit both the API and the cocrystal former are colorless. Crystallization from ethanol, isopropanol, ethanol-water (v/v, 1/1) mixture, and acetonitrile yielded pale yellow (form II, thin needles) and orange (form 1II, blocks) cocrystals concomitantly. Needles appeared from solution within a day, while the blocks were obtained after 1-2 days from the same flask, indicating that yellow needles were formed faster and the orange blocks were perhaps formed under thermodynamic conditions. Form 1I cocrystals could also be produced from the variety of common solvents. Cocrystallization of FS with 2,2'-bipyridine (2BPY) and 4-aminopyridine (4AP) gave colorless cocrystals 2 and 3, respectively, and did not exhibit polymorphism. The single-crystal X-ray structures, powder X-ray diffraction, photophysical characterization, differential scanning calorimetry, hot stage microscopy studies, and density functional theory (DFT) calculations provide insight into the structure property relationship. The common structural features observed in all of the structures is the formation of sandwich motifs comprising FS and pyridines through pi-stacking interactions. These motifs are linked differently through hydrogen bonding interactions in all three directions. The significant color difference between the two cocrystals dimorphs could be attributed to the different pi-stacking patterns and hydrogen bonding interactions between molecules of FS and 4BPY in their cocrystal structures. Investigation on the origin of the color difference using DFT calculations revealed the decrease in HOMO-LUMO gap for form 1II cocrystals (orange) compared to form 1I crystals (light yellow). The crystal-to-crystal thermal transformation of form 1I crystals to form 1II crystals of 1 suggests the role of pi-stacking assemblies in driving the self-assembly.</p>1 aSangtani, Ekta1 aSahu, Sanjay, Kumar1 aThorat, Shridhar, H.1 aGawade, Rupesh, L.1 aJha, Kunal, K.1 aMunshi, Parthapratim1 aGonnade, Rajesh, G.  uhttps://library.ncl.res.in/content/furosemide-cocrystals-pyridines-interesting-case-color-cocrystal-polymorphism-001514nas a2200277   4500008004100000022001400041245015400055210006900209260000800278300001400286490000600300520045800306653000600764653003100770653001400801653007000815653004300885653001900928100002700947700002400974700003200998700002501030700002401055700002601079856013101105       2017                        eng d  a2365-654900aFacile one-pot multi-component synthesis of spirooxindoles and 3, 3 `-disubstituted oxindoles via sp(3) C-H activation/functionalization of azaarenes0 aFacile onepot multicomponent synthesis of spirooxindoles and 3 3  cSEP  a9147-91520 v23 a<p>A novel one-pot multicomponent reaction (MCR) protocol has been demonstrated for the first time for sustainable and facile synthesis of spirooxindoles and 3, 3 `-disubstituted oxindoles in an excellent yield via sp(3) C-H activation/functionalization of 2-methyl azaarenes and (2-azaaryl)methanes with isatin, active methylene compounds using eco-friendly heterogeneous, reusable silica-supported dodecatungstophosphoric acid (DTP/SiO2) catalyst.</p>10a310a3'-disubstituted oxindoles10aazaarenes10asilica-supported dodecatungstophosphoric acid (DTP/SiO2) catalyst10asp(3) C-H activation/functionalization10aspirooxindoles1 aPathan, Mohsinkhan, Y.1 aChavan, Santosh, S.1 aShaikh, Taufeekaslam, M. Y.1 aThorat, Shridhar, H.1 aGonnade, Rajesh, G.1 aMulla, Shafeek, A. R.  uhttps://library.ncl.res.in/content/facile-one-pot-multi-component-synthesis-spirooxindoles-and-3-3-disubstituted-oxindoles-sp3