157071-79-9Relevant academic research and scientific papers
Amination of Aromatic Halides and Exploration of the Reactivity Sequence of Aromatic Halides
Yang, Chu,Zhang, Feng,Deng, Guo-Jun,Gong, Hang
, p. 181 - 190 (2019/01/10)
A base-promoted amination of aromatic halides has been developed using a limited amount of dimethylformamide (DMF) or amine as an amino source. Various aryl halides, including F, Cl, Br, and I, have been successfully aminated in good to excellent yields. Although the amination of aromatic halides with amines or DMF is usually considered as an aromatic nucleophilic substitution (SNAr) process, and the reactivity of an aromatic halide is F > Cl > Br > I, the reactivity of aromatic halides in this system was found to be I > Br a‰ F > Cl. This protocol also showed a good regioselectivity for multihalogenated aromatics. This protocol is valuable for industrial application due to the simplicity of operation, the unrestricted availability of amino sources and aromatic halides, transition metal-free conditions, no requirement for solvent, and scalability.
Alcoholysis of trifluoromethyl groups attached to the pyridine ring
Qian, Xuhong,Liu, Shuyou
, p. 9 - 12 (2007/10/03)
In dimethylformamide solution, trifluoroethoxylation and methoxylation of 5-chloro-3-trifluoromethylpyridine (2) yield 5-chloro-3-tris(trifluoroethoxyl)methyl pyridine (2a) and a dimethyl ketal of 3-chloronicotinic acid anhydride (2b) with fluorines as leaving groups, respectively. The corresponding reactions of 2,3-dichloro-5-trifluoromethylpyridine (3) only yield the 2-alkoxy-substituted products 3a and 3b with chloro as the leaving group and the 2-dimethylamino product 3c which was formed by the action of solvent dimethylformamide as a nucleophile. Differences in their reaction behaviour and possible mechanisms are also discussed.
