摘要
目的利用卤代芳烃的亲核取代反应在芳环中引入二甲氨基,探讨反应条件对硝基取代的芳香卤代烃胺化反应的影响。方法以2-溴-1-氟-4-硝基苯作为模型探究最佳反应条件,并用不同位置、不同卤原子取代的硝基苯探究反应底物的范围。结果反应最佳反应条件为使用1.00 mL的N,N-二甲基甲酰胺(N,N-dimethylformamide,DMF)为胺化剂,1.5倍当量KOH提供碱性环境,5.00 mL的低共熔溶剂(deep eutectic solvents,DESs)(氯化胆碱∶甘油=1∶2)为溶剂,在80℃下反应24 h。在底物范围扩展中有效得到一系列4-二甲氨基硝基苯化合物及其衍生物,经1H-NMR、13C-NMR确证其结构。结论DMF在DESs中可以有效充当二甲氨基化试剂,DESs溶剂选择性提高硝基对位上的卤原子的亲核取代反应活性,且不活化邻位卤原子,在优化后的最佳条件下反应,最高产率可达84%。这种特殊的区域选择性是其他溶剂中不具备的优势,同时该方法具有绿色环保、简单方便、产率适中的特点。
Objective To investigate the effects of reaction conditions on the amination of nitro-substituted aromatic halogenated hydrocarbons using the nucleophilic substitution reaction of halogenated aromatic hydrocarbons to introduce dimethylamine into the aromatic ring.Methods The optimal reaction conditions were explored using 2-bromo-1-fluoro-4-nitrobenzene as a model,and the range of reaction substrates was explored with nitrobenzene substituted at different positions and different halogen atoms.Results The optimal reaction conditions were as follows:1.00 mL of N,N-dimethylformamide(DMF)was used as aminating agent,1.5 equivalents of KOH was used to provide alkaline environment,5.00 mL of deep eutectic solvents(DESs)(choline chloride:glycerol=1:2)was used as solvent,and the reaction was carried out at 80℃for 24 h.A series of 4-dimethylamino nitrobenzene compounds and their derivatives were effectively obtained in the expansion of the substrates,and their structures were confirmed by 1H-NMR and 13C-NMR.Conclusion DMF can effectively act as a dimethyl amination reagent in DESs,which selectively improves the reactivity of nucleophilic substitution of halogen atoms at the para position of the nitro group while not activating the halogen atoms at the ortho position.Under optimized conditions,the highest yield can reach 84%.This unique regioselectivity is an advantage not found in other solvents.At the same time,this method is environmentally friendly,simple and convenient,and has a moderate yield.
作者
王婕
李珍珍
潘彤
饶立航
黄甲想
蒋琪
盛文兵
WANG Jie;LI Zhenzhen;PAN Tong;RAO Lihang;HUANG Jiaxiang;JIANG Qi;SHENG Wenbing(School of Pharmacy,Hunan University of Chinese Medicine,Changsha,Hunan 410208,China)
出处
《湖南中医药大学学报》
CAS
2024年第7期1213-1218,共6页
Journal of Hunan University of Chinese Medicine
基金
湖南省教育厅科研项目重点项目(21A0239)
国家大学生创新创业训练计划项目(S202310541069)。