학술논문
Fine tuning of folded conformation by change of substituents: 1 H NMR and crystallographic evidence for folded conformation due to arene interactions in pyrazolo[3,4-d]pyrimidine core based ‘propylene linker’ compounds
Document Type
Article
Author
Source
Subject
*PYRAZOLONES
*CRYSTALLOGRAPHY
*SPECTRUM analysis
*X-ray crystallography
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Language
ISSN
0022-2860
Abstract
Abstract: Proton NMR and X-ray crystallographic analysis of two newly synthesized ‘trimethylene linker,’ (Leonard linker) compounds 1,3-bis(4-ethoxy-6-methylsulfanyl-lH-pyrazolo[3,4-d]pyrimidin-1-yl)propane (4c) and 1,3-bis(4-isopropoxy-6-methylsulfanyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)propane (4d) show intramolecularly stacked conformations both in solution and solid state. Robustness of the unusual U-motif formed due to intramolecular stacking in earlier related compounds (1, n=3 and 3, n=3) is not only confirmed but additional fine tuning is also achieved in new compounds (4) formed by replacement of remote 4-alkylsulfanyl group in 1a by 4-alkoxy substituents. [Copyright &y& Elsevier]