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%。