3468-53-9Relevant articles and documents
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Badgett,Woodward
, p. 2907 (1947)
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Mechanically induced solvent-free esterification method at room temperature
Zheng, Lei,Sun, Chen,Xu, Wenhao,Dushkin, Alexandr V.,Polyakov, Nikolay,Su, Weike,Yu, Jingbo
, p. 5080 - 5085 (2021/02/05)
Herein, we describe two novel strategies for the synthesis of esters, as achieved under high-speed ball-milling (HSBM) conditions at room temperature. In the presence of I2 and KH2PO2, the reactions afford the desired esterification derivatives in 45% to 91% yields within 20 min of grinding. Meanwhile, using KI and P(OEt)3, esterification products can be obtained in 24% to 85% yields after 60 min of grinding. In addition, the I2/KH2PO2 protocol was successfully extended to the late-stage diversification of natural products showing the robustness of this useful approach. Further application of this method in the synthesis of inositol nicotinate was also discussed. This journal is
Orientation-dependent conformational polymorphs in two similar pyridine/pyrazine phenolic esters
Samie, Ali,Salimi, Alireza
, p. 3721 - 3730 (2019/06/21)
On the basis of crystal engineering, two similar esters of phenyl pyridine-2-carboxylate (I) and phenyl pyrazine-2-carboxylate (II) were designed and synthesized. The compounds were characterized using FT-IR, mass spectrometry, CHN-elemental analyses, NMR and PXRD. For each compound, two polymorphs were obtained (Ia, Ib and IIa, IIb) and identified by TGA, DSC and SCXRD. A comparison of the crystal structures of the polymorphs revealed that the different torsion angles of the pyrazine (τ1) and phenyl (τ2) rings to the ester backbone resulted in the conformers I and II, respectively. Theoretical criteria (max(Δθ), rmsd[r]-crystal, energy profile) confirmed that the structural differences in the conformers are in the range of acceptable values for the detection of conformational changes. The phase stability of the polymorphs was investigated by slurry and grinding methods as well as by the HSM technique. Since the orientations of pyrazine and phenyl moieties were altered in the polymorphs, the hydrogen bond donor and acceptors exhibited meaningful supramolecular architectures in the crystal packing as well as C-H?N, C-H?O and C-H?π interactions. The energetic study of the noncovalent interactions in the molecular pairs (dimers) of the polymorph crystal structures was performed by DFT-D calculations.
