作者:B. V. Lyalin、V. A. Petrosyan、B. I. Ugrak
DOI:10.1007/s11172-010-0004-8
日期:2009.2
4-Chlorosubstituted pyrazolecarboxylic acids were synthesized via chlorination of the corresponding acids at the Pt anode in NaCl aqueous solutions under conditions of divided galvanostatic electrolysis. The efficiency of the process depends on the structures of the initial pyrazolecarboxylic acids, particularly, on the donor-acceptor properties of the substituents and on their position in the pyrazole ring. The yields of the 4-chlorosubstituted products of chlorination of pyrazole-3(5)-carboxylic acid, 1-methylpyrazole-5-carboxylic acid, 1-methyl-pyrazole-3-carboxylic acid, 1-ethylpyrazole-3-carboxylic acid, and 1-methyl-3-nitropyrazole- 5-carboxylic acid are 92, 93, 69, 80, and 4%, respectively.
4-氯取代吡唑羧酸是通过在分压恒流电解条件下,在氯化钠水溶液中,在铂阳极对相应的酸进行氯化而合成的。该过程的效率取决于初始吡唑羧酸的结构,特别是取代基的供体-受体性质及其在吡唑环中的位置。吡唑-3(5)-羧酸、1-甲基吡唑-5-羧酸、1-甲基吡唑-3-羧酸、1-乙基吡唑-3-羧酸和1-甲基-3-硝基吡唑-5-羧酸的4-氯取代氯化产物的产量分别为92%、93%、69%、80%和4%。