Mnguni Malitsatsi J, Lemmerer Andreas
Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, PO Wits 2050, South Africa.
Acta Crystallogr C Struct Chem. 2015 Feb;71(Pt 2):103-9. doi: 10.1107/S2053229614027247. Epub 2015 Jan 12.
Six derivatives of 4-amino-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one (4-aminoantipyrine), C11H13N3O, (I), have been synthesized and structurally characterized to investigate the changes in the observed hydrogen-bonding motifs compared to the original 4-aminoantipyrine. The derivatives were synthesized from the reactions of 4-aminoantipyrine with various aldehyde-, ketone- and ester-containing molecules, producing (Z)-methyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enoate, C16H19N3O3, (II), (Z)-ethyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enoate, C17H21N3O3, (III), ethyl 2-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]cyclohex-1-enecarboxylate, C20H25N3O3, (IV), (Z)-ethyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]-3-phenylacrylate, C22H23N3O3, (V), 2-cyano-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C14H14N4O2, (VI), and (E)-methyl 4-{[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]methyl}benzoate, C20H19N3O3, (VII). The asymmetric units of all these compounds have one molecule on a general position. The hydrogen bonding in (I) forms chains of molecules via intermolecular N-H...O hydrogen bonds around a crystallographic sixfold screw axis. In contrast, the formation of enamines for all derived compounds except (VII) favours the formation of a six-membered intramolecular N-H...O hydrogen-bonded ring in (II)-(V) and an intermolecular N-H...O hydrogen bond in (VI), whereas there is an intramolecular C-H...O hydrogen bond in the structure of imine (VII). All the reported compounds, except for (II), feature π-π interactions, while C-H...π interactions are observed in (II), C-H...O interactions are observed in (I), (III), (V) and (VI), and a C-O...π interaction is observed in (II).
已合成并对4-氨基-1,5-二甲基-2-苯基-2,3-二氢-1H-吡唑-3-酮（4-氨基安替比林）C₁₁H₁₃N₃O（I）的六种衍生物进行了结构表征，以研究与原始4-氨基安替比林相比，所观察到的氢键模式的变化。这些衍生物由4-氨基安替比林与各种含醛、酮和酯的分子反应合成，产物包括（Z）-3-[(1,5-二甲基-3-氧代-2-苯基-2,3-二氢-1H-吡唑-4-基)氨基]丁酸甲酯C₁₆H₁₉N₃O₃（II）、（Z）-3-[(1,5-二甲基-3-氧代-2-苯基-2,3-二氢-1H-吡唑-4-基)氨基]丁酸乙酯C₁₇H₂₁N₃O₃（III）、2-[(1,5-二甲基-3-氧代-2-苯基-2,3-二氢-1H-吡唑-4-基)氨基]环己-1-烯羧酸乙酯C₂₀H₂₅N₃O₃（IV）、（Z）-3-[(1,5-二甲基-3-氧代-2-苯基-2,3-二氢-1H-吡唑-4-基)氨基]-3-苯基丙烯酸乙酯C₂₂H₂₃N₃O₃（V）、2-氰基-N-(1,5-二甲基-3-氧代-2-苯基-2,3-二氢-1H-吡唑-4-基)乙酰胺C₁₄H₁₄N₄O₂（VI）以及（E）-4-{[(1,5-二甲基-3-氧代-2-苯基-2,3-二氢-1H-吡唑-4-基)氨基]甲基}苯甲酸甲酯C₂₀H₁₉N₃O₃（VII）。所有这些化合物的不对称单元在一般位置上均有一个分子。（I）中的氢键通过围绕晶体学六重螺旋轴的分子间N-H...O氢键形成分子链。相比之下，除（VII）外的所有衍生化合物中烯胺的形成有利于在（II）-（V）中形成六元分子内N-H...O氢键环以及在（VI）中形成分子间N-H...O氢键，而在亚胺（VII）的结构中有一个分子内C-H...O氢键。除（II）外，所有报道的化合物均具有π-π相互作用，而在（II）中观察到C-H...π相互作用，在（I）、（III）、（V）和（VI）中观察到C-H...O相互作用，在（II）中观察到C-O...π相互作用。
