1724-02-3Relevant articles and documents
Preparation method of 3-substituted dimethyl glutarate and dimethyl glutaconate
-
Paragraph 0032-0034, (2018/09/08)
The invention relates to the field of fine chemical engineering, and particularly relates to a preparation method of 3-substituted dimethyl pentodiate and pentene diester. According to the preparationmethod of 3-substituted dimethyl pentodiate and pentene diester, malonic ester and halomethane are used as raw materials, substitution reaction is performed under an alkaline action, then decarboxylation and esterification reaction are performed so as to prepare 3-substituted dimethyl pentodiate or pentene diester, a structural formula of 3-substituted dimethyl pentodiate is as shown in a compound (V), and a structural formula of pentene diester is as shown in a compound (IX). The preparation method of 3-substituted dimethyl pentodiate and pentene diester is mild in reaction conditions, is easy to operate and is safe. The formula is shown in the description.
Fabrication of a novel PbO2 electrode with a graphene nanosheet interlayer for electrochemical oxidation of 2-chlorophenol
Duan, Xiaoyue,Zhao, Cuimei,Liu, Wei,Zhao, Xuesong,Chang, Limin
, p. 424 - 436 (2017/04/28)
A novel PbO2 electrode with a graphene nanosheet interlayer (marked as GNS-PbO2) was prepared combining electrophoretic deposition and electro-deposition technologies. The micro morphology, crystal structure and surface chemical states of GNS-PbO2 electrodes were characterized using scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Their electrochemical properties and stability were determined using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ·OH radicals test and accelerated life test, and compared with traditional PbO2 electrodes. Besides, their potential application in the electrochemical degradation of 2-chlorophenol (2-CP) was investigated. The GNS-PbO2 electrode possessed perfect octahedral β-PbO2 microcrystals, and its grain size was much smaller than that of traditional PbO2 electrode. It exhibited higher electrochemical activity than traditional PbO2 electrode due to its larger electrochemical active surface area and stronger ·OH radicals generation ability. The service lifetime of GNS-PbO2 electrode (107.9?h) was 1.93 times longer than that of traditional PbO2 electrode (55.9?h). The electrochemical degradation rate constant of 2-CP on GNS-PbO2 electrode (kapp?=?2.75?×?10?2?min?1) is much higher than for PbO2 electrode (kapp?=?1.76?×?10?2?min?1). 2-CP oxidation yielded intermediates including aromatic compounds (catechol, phenol and ortho-benzoquinone) and organic acids (oxalic acid, maleic acid and glutaconic acid), and a possible degradation pathway for 2-CP was proposed accordingly.
Amidine dications as superelectrophiles
Corr, Michael J.,Roydhouse, Mark D.,Gibson, Kirsty F.,Zhou, Sheng-Ze,Kennedy, Alan R.,Murphy, John A.
supporting information; experimental part, p. 17980 - 17985 (2010/04/01)
2-Dimethylalkylammonium pyridinium and 2-dimethylalkylammonium pyrimidinium ditriflate salts are very powerful methylating agents toward phosphorus (triphenylphosphine) and nitrogen (triethylamine) nucleophiles. In competition experiments with triethylamine as nucleophile, these N-methyl disalts are more reactive methylating agents than dimethyl sulfate. Reaction of the pyridinium dications with water as an oxygen nucleophile leads to attack at the 2-position of the heteroaromatic ring and displacement of an ammonium group; 2-hydroxypyridinium compounds are formed in the first instance, which are easily converted to 2-pyridones. Extending the scope of the reactions, a tricationic 2,6-bis(dimethylalkylammonium) pyridinium salt has also been prepared and characterized and its reactivity as a methylating agent assessed in comparison with that of the dications.
