- Hexagonal host framework of sym-aryloxytriazines stabilised by weak intermolecular interactions
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2,4,6-Tris(4-halophenoxy)-1,3,5-triazine 1 is a convenient C3 starting material for the self-assembly of hexagonal open frameworks mediated via the halogen...halogen trimer synthon and the π-stacked Piedfort Unit (PU). We examine in this paper crystal structures of 2,4,6-tris(2-iodo-3- pyridyloxy)-1,3,5-triazine 2, 2,4,6-tris (3-iodophenoxy)-1,3,5-triazine 3, 2,4,6-tris(6-methyl-3-pyridyloxy)-1,3,5-triazine 4, and 2,4,6-tris[4-(4′- bromophenyl) phenoxy)]-1,3,5-triazine 5. Triazine 2 forms isostructural 2:1 host·guest adducts (guest = mesitylene, collidine) in the rhombohedral space group R3 such that the host architecture is stabilised by the C 3i-PU and a helix of C-H...N interactions. The crystal structure of 3 is different from its chloro/bromo derivatives signifying the importance of the more polarisable I atom compared to Cl, Br. Pairs of C-H...O and C-H...N hydrogen bonds and C3i-PU sustain the columnar structure of 3 (space group R3). The PU has pseudo trigonal symmetry in picolinoxy triazine 4 (space group P21/n). In contrast to the phenyl derivatives, the extended aryl arms in biphenyl 5 do not adopt a trigonal conformation: two biphenyl groups are oriented parallel that participate in Br...Br and Br...π interactions. We note that 1 and 2 readily form hexagonal host lattices for guest inclusion, while 3, 4, and 5 crystallise in solvent-free form. Thermal measurements (TGA, DSC) indicate that guest release occurs at a higher temperature in the cage type host·guest clathrates compared to the channel inclusion compounds for the same solvent. Statistics from the Cambridge Structural Database using CSD Symmetry show that the phenoxytriazine scaffold is unique among the trigonal molecules for the carry-over of symmetry relation from molecule to crystal. The ease of predicting crystal packing and space group in this family of compounds (1, 2) makes them good candidates for the crystal engineering of host frameworks.
- Saha, Binoy K.,Aitipamula, Srinivasulu,Banerjee, Rahul,Nangia, Ashwini,Jetti, Ram K. R.,Boese, Roland,Lam, Chi-Keung,Mak, Thomas C. W.
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- Solid-state fluorescence of zwitterionic imidazolium pyridinolates bearing long alkyl chains: Control of emission properties based on variation of lamellar alignment
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Herein, the control of the crystalline-state fluorescence of zwitterionic imidazolium 2-pyridin-3-olate 1 bearing linear alkyl chains via morphological variations is described, along with a mechanistic rationale. Crystals of 1a–e prepared from CH3CN exhibited intense blue fluorescence under UV irradiation at 298 K, whereas crystals of 1e prepared from i-PrOH/Et2O were less emissive under the same measurement conditions. Temperature-dependent emission spectra showed that emissive crystals of 1a–e experienced minimal emission decay with increasing temperature, whereas crystalline 1e, having a different polymorphism, was highly heat-quenchable. Single-crystal XRD established that less emissive, heat-quenchable crystal 1e had a lamellar structure supported by consecutive face-to-face arrangement with π-stacking interactions between imidazolium and pyridinolate moieties, whereas highly emissive, heat-resistant crystals 1d and 1e had a face-to-edge lamellar structure with CH-π interactions between the heteroaromatic rings.
- Yoshida, Atsushi,Ikeshita, Masahiro,Komiya, Naruyoshi,Naota, Takeshi
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- Synthetic method of 3, 4-dihydro-2H-pyran [3, 2-b] pyridine
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The invention relates to a synthetic method of 3, 4-dihydro-2H-pyran [3, 2-b] pyridine, and mainly solves the technical problems that according to an existing synthetic method, raw materials are not easily acquired, reaction steps are long, palladium catalysis hydrogenation and debenzylation are achieved by the aid of precious metal palladium, and precious metal palladium is difficultly recycled.The technical scheme includes a synthetic method of the 3, 4-dihydro-2H-pyran [3, 2-b] pyridine. The synthetic method is characterized by including the steps: firstly, adding iodine into sodium carbonate solution with 3-pyridone to obtain a compound 1; secondly, reacting the compound 1 with 1, 3-dibromopropane under presence of alkali compounds, and stirring mixture at the indoor temperature overnight to obtain a compound 2; thirdly, reacting the compound 2 with n-butyllithium in tetrahydrofuran at the lower temperature to obtain a target compound 3, 4 dihydro-2H-pyran [3, 2-b] pyridine. The pyridine is provided with important framework structures of synthetic drugs.
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Paragraph 0009
(2018/03/25)
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- INHIBITORS OF THE KYNURENINE PATHWAY
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The present application provides novel inhibitors of indoleamine 2,3-dioxygenase-1 and/or indoleamine 2,3-dioxygenase-2 and/or tryptophan 2,3-dioxygenase, metabolites thereof, and phannaceutically acceptable salts or prodrugs thereof. Also provided are methods for preparing these compounds. A therapeutically effective amount of one or more of the compounds of formula (I) is useful in treating diseases resulting from dysregulation of the kynurenine pathway. Compounds of formula (I) act by inhibiting the enzymatic activity or expression of indoleamine 2,3-dioxygenase-1 and/or indoleamine 2,3-dioxygenase-2 and/or tryptophan 2,3-dioxygenase.
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Page/Page column 199; 200
(2014/12/12)
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- First synthesis of 4-aminopyrido[2′,3′:4,5]furo[3,2-d] pyrimidines
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This Letter describes for the first time the synthesis of pyrido[2′,3′:4,5]furo[3,2-d]pyrimidines substituted by a primary or secondary amino group on position 4 of the pyrimidine ring. Application of microwave irradiation technology allowed fast and convenient procedures.
- Loidreau, Yvonnick,Marchand, Pascal,Dubouilh-Benard, Carole,Nourrisson, Marie-Renée,Duflos, Muriel,Besson, Thierry
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supporting information; experimental part
p. 944 - 947
(2012/03/11)
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- Domino ring-opening/carboxamidation reactions of N-tosyl aziridines and 2-halophenols/pyridinol: Efficient synthesis of 1,4-benzo- And pyrido-oxazepinones
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"Chemical Equation Presented" A domino process is described for the synthesis of 1,4-benzo- and pyrido-oxazepinones by one-pot sequential ring-opening/carboxamidation reactions of various N-tosylaziridines with a range of 2-halophenols/pyridinol under phase-transfer catalysis.
- Chouhan, Gagan,Alper, Howard
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supporting information; experimental part
p. 192 - 195
(2010/04/02)
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- Fused pyridine derivatives
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The present provides a condensed pyridine compound (I) represented by the following formula: (wherein, R2represents ring A represents benzene ring, pyridine ring, thiophene ring or furan ring; and B represents its pharmaceutically acceptable salt or hydrates thereof, which is a clinically useful medicament having a serotonin antagonism, in particular, that for treating, ameliorating or preventing spastic paralysis or central muscle relaxants for ameliorating myotonia.
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- Heterocyclic thione
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A solvent soluble heterocyclic o-hydroxy thione carrying a lipophilic group and the process for the selective extraction of gallium, and certain other related metals, especially from solutions containing excess aluminium.
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