40263-57-8Relevant articles and documents
Hexagonal host framework of sym-aryloxytriazines stabilised by weak intermolecular interactions
Saha, Binoy K.,Aitipamula, Srinivasulu,Banerjee, Rahul,Nangia, Ashwini,Jetti, Ram K. R.,Boese, Roland,Lam, Chi-Keung,Mak, Thomas C. W.
, p. 295 - 316 (2005)
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.
Synthetic method of 3, 4-dihydro-2H-pyran [3, 2-b] pyridine
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Paragraph 0009, (2018/03/25)
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.
First synthesis of 4-aminopyrido[2′,3′:4,5]furo[3,2-d] pyrimidines
Loidreau, Yvonnick,Marchand, Pascal,Dubouilh-Benard, Carole,Nourrisson, Marie-Renée,Duflos, Muriel,Besson, Thierry
supporting information; experimental part, p. 944 - 947 (2012/03/11)
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.