931-19-1Relevant articles and documents
Rapid and Effective Reaction of 2-Methylpyridin-N-oxides with Triphosgene via a [3,3]-Sigmatropic Rearrangement: Mechanism and Applications
Li, Hao,Nie, Fang-Yuan,Song, Qin-Hua,Xia, Hong-Cheng
, p. 8308 - 8318 (2021/06/28)
A facile and effective synthesis of 2-chloromethylpyridines was developed by a one-pot reaction of 2-alkylpyridin-N-oxides and triphosgene at room temperature. As starting materials, N-oxides of 2-alkylpyridine derivatives, including 2-alkylpyridines, 2-methyl quinolines, and phenanthroline, can react rapidly with triphosgene in the presence of triethylamine, affording 2-chloromethylpyridines in good to excellent yields (52-95%). Using the 2-methylquinoline substrate for the mechanistic study, it has been well demonstrated that the chlorination reaction undergoes a [3,3]-sigmatropic rearrangement, which can be observed as a reversible process by monitoring the intermediates. Moreover, the chlorination reaction can be used to construct a rapid and sensitive fluorescent probe for the detection of phosgene.
Synthetic method 2 -methylpyridine - N - oxide
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Paragraph 0030-0109, (2021/10/27)
The invention discloses a synthetic method of 2 - methylpyridine - N - oxide, and belongs to the technical field of pesticide/pharmaceutical chemicals intermediates. The synthesis method takes benzene as a solvent, uses molybdenum oxide and TEBA as a composite catalyst in the reaction process, and comprises the following steps: (1) dissolving 2 - methylpyridine in benzene to obtain the reaction liquid A. (2) Hydrogen peroxide was slowly added to reaction solution A at low temperature, and molybdenum oxide and TEBA were added to react, and the reaction 3 - 5 hours was followed, and 2 - and the low temperature condition was 0.5% 50 °C. (3) After completion of the reaction, the benzene was distilled off under reduced pressure to obtain 2 -methylpyridine - N - oxide. The method takes benzene as a solvent, uses molybdenum oxide and TEBA as a composite catalyst, slowly drops into hydrogen peroxide, effectively controls the generation of side reactions, and directly reacts the product purity up to 99% or more.
Visible-Light-Induced ortho-Selective Migration on Pyridyl Ring: Trifluoromethylative Pyridylation of Unactivated Alkenes
Jeon, Jinwon,He, Yu-Tao,Shin, Sanghoon,Hong, Sungwoo
supporting information, p. 281 - 285 (2019/11/26)
The photocatalyzed ortho-selective migration on a pyridyl ring has been achieved for the site-selective trifluoromethylative pyridylation of unactivated alkenes. The overall process is initiated by the selective addition of a CF3 radical to the alkene to provide a nucleophilic alkyl radical intermediate, which enables an intramolecular endo addition exclusively to the ortho-position of the pyridinium salt. Both secondary and tertiary alkyl radicals are well-suited for addition to the C2-position of pyridinium salts to ultimately provide synthetically valuable C2-fluoroalkyl functionalized pyridines. Moreover, the method was successfully applied to the reaction with P-centered radicals. The utility of this transformation was further demonstrated by the late-stage functionalization of complex bioactive molecules.
