New approach to electrochemical iodination of arenes exemplified by the synthesis of 4-iodopyrazoles of different structures
作者:B. V. Lyalin、V. A. Petrosyan
DOI:10.1007/s11172-014-0438-5
日期:2014.2
The two-stage electrosynthesis of 4-iodosubstituted pyrazole derivatives was performed. At the first stage, KIO3 was obtained at the Ni anode under the undivided galvanostatic conditions of electrolysis of an aqueous alkaline solution of KI (or I2) at the Ni anode. At the second stage, pyrazole and its derivatives were iodinated in the heterophase (H2O-CHCl3 (CCl4)) medium by the KIO3-KI (or KIO3-I2) system in the presence of H2SO4. The yields of iodopyrazoles were 74–92%. The electrochemical iodination of anisole, 2-methylpyrazole, and thiophene was carried out to form 4-iodoanisole (88% yield), 4,5-diiodo-2-methylimidazole (54% yield), and a mixture of 2-iodothiophene (60% yield) and 2,5-diiodothiophene (4% yield).
Electrosynthesis of 4-iodopyrazole and its derivatives
作者:B. V. Lyalin、V. A. Petrosyan、B. I. Ugrak
DOI:10.1007/s11172-010-0277-y
日期:2010.8
Electrosynthesis of 4-iodo-substituted pyrazoles has been accomplished by iodination of the corresponding precursors on a Pt-anode in aqueous solutions of KI under conditions of the diaphragm galvanostatic electrolysis. Efficiency of the process depends on the donor-acceptor properties of substituents and their positions in the pyrazole ring. Thus, iodination of pyrazole, 3,5-dimethylpyrazole, 3-nitropyrazole
Efficient iodination of structurally varying pyrazoles in heterophase medium
作者:B. V. Lyalin、V. A. Petrosyan
DOI:10.1007/s11172-013-0140-z
日期:2013.4
A synthesis of 4-iodo-substituted pyrazoles by iodination of pyrazole and its derivatives in the heterophase (H2O/CHCl3 (CCl4)) medium with the system KI-KIO3 in the presence of H2SO4 additives was accomplished. The yields of 4-iodo-substituted pyrazoles in the iodination of pyrazole, 3,5-dimethylpyrazole, pyrazole-3(5)-carboxylic acid, 1-methylpyrazole-3-carboxylic acid, 1-methylpyrazole-5-carboxylic acid, 3-nitropyrazole, 1-methyl-3-nitropyrazole, 1-methylpyrazole, 1-ethylpyrazole, and 1-isopropylpyrazole were within 80–97%, whereas in the case of 3-nitropyrazole-5-carboxylic acid it was 32%.
for the intramolecularcyclization of tertiary alcohols with terminal alkynes to form diverse aza-spirocycles. The reaction was carried out with low catalyst loading under microwave irradiation to give both sulfonylated and acylated spirocyclic nitrogen derivatives. Gram scale spirocyclization was carried out to demonstrate the robustness of the reaction. An intramolecular Mizoroki-Heck reaction was performed
Design, synthesis, and evaluation of 3,4-disubstituted pyrazole analogues as anti-tumor CDK inhibitors
作者:Ronghui Lin、George Chiu、Yang Yu、Peter J. Connolly、Shengjian Li、Yanhua Lu、Mary Adams、Angel R. Fuentes-Pesquera、Stuart L. Emanuel、Lee M. Greenberger
DOI:10.1016/j.bmcl.2007.05.092
日期:2007.8
3-(benzimidazol-2-yl)-4-[2-(pyridin-3-yl)-vinyl]-pyrazoles (2) and 3-(imidazol-2-yl)-4-[2-(pyridin-3-yl)-vinyl]-pyrazoles (3), were synthesized as novel cyclin-dependent kinase (CDK) inhibitors. Representative compounds showed potent and selective CDK inhibitory activities and inhibited in vitro cellular proliferation in various human tumor cells. The design, synthesis, and preliminary biological evaluation of