288-13-1Relevant articles and documents
Copper (II) complexes with novel Schiff-based ligands: synthesis, crystal structure, thermal (TGA–DSC/FT-IR), spectroscopic (FT-IR, UV-Vis) and theoretical studies
Moreira, Jeniffer Meyer,Campos, Guilherme Fava,de Campos Pinto, Leandro Moreira,Martins, Gabriel Rodrigues,Tirloni, Bárbara,Schwalm, Cristiane Storck,de Carvalho, Cláudio Teodoro
, p. 4087 - 4098 (2022)
This study aimed to synthesize two novel Schiff-base ligands through the condensation between N-(2-aminoethyl)pyrazoles and 2-hydroxy-1-naphthaldehyde, which are: NaphPz ((E)-1-(((2-(1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol)) and NaphDPz ((E)-1-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol). These novel pyrazole-imines were synthesized, characterized and used as copper (II) ion complexing agents. Different synthetic routes have been adapted to obtain the [Cu(NaphPz)Cl], [Cu(NaphDPz)Cl] and [Cu(NaphPz)2] complexes in the solid state, the first two in the crystalline form and the latter as a powder. The minimum metal–ligand stoichiometry for the three complexes was defined by TGA–DSC thermoanalytical data and by single-crystal X-ray diffraction for the crystalline samples which belong to the P21/n space group. The products of the thermal decomposition of the material were also monitored by TGA–DSC/FT-IR in air and N2 atmospheres in order to suggest how thermal decomposition of the organic portion of the complex occurs. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations compared to experimental results (UV-Vis and FT-IR) show a high degree of correlation. From HOMO/LUMO orbitals, the main major charge distributions, responsible for the absorption bands of the complexes, were determined.
Unexpected ring opening of pyrazolines with activated alkynes: synthesis of 1H-pyrazole-4,5-dicarboxylates and chromenopyrazolecarboxylates
Bhimapaka, China Raju,Kolla, Sai Teja,Rayala, Nageswara Rao,Sridhar, Balasubramanian
supporting information, p. 334 - 338 (2022/01/20)
1H-Pyrazole-4,5-dicarboxylates and chromenopyrazole carboxylates were prepared by reacting pyrazolines with activated alkynes under neat conditions without a catalyst. The products were formed via unexpected ring opening of pyrazolines with the elimination of styrene/ethylene. These types of transformations are unknown and the products formed were confirmed using their spectral/analytical data. In addition, the structures of compounds 5e and 5n were confirmed by single-crystal X-ray analysis. Control experiments were conducted to support the proposed reaction mechanism.
Preparation method of dinotefuran
-
Paragraph 0013; 0048-0053, (2021/08/07)
The invention provides a preparation method of dinotefuran, and belongs to the field of organic synthesis. The invention provides a preparation method of dinotefuran, which is characterized by comprising the following steps: step 1, adding a compound I, a compound II and a solvent into a reaction container, heating to 50 DEG C which is the reflux temperature of the solvent, reacting for 1-24 hours, then adding tetrahydrofuran-3-methylamine, and continuously reacting for 1-24 hours to obtain a reaction solution; and 2, cooling the reaction solution to 0-20 DEG C, standing, filtering, separating the solid and filtrate, and purifying the solid to obtain dinotefuran, wherein the structural formula of the compound I is shown in the specification, the structural formula of the compound II is shown in the specification, and R1 and R2 are independently selected from any one of H, C1-C5 alkyl and C1-C5 alkyl substituted by at least one halogen atom. According to the invention, a brand new dinotefuran synthesis route is developed, the synthesis route is greatly shortened, and the production efficiency is improved.
