2-对二甲氨基苯基-5-氟-6-吗啉苯并咪唑的合成及其光谱学性质研究

合成了一种新的取代苯并咪唑化合物 ,2 对二甲氨基苯基 5 氟 6 吗啉苯并咪唑 ,采用紫外 可见光谱、荧光光谱及荧光寿命等方法探讨了溶液pH值对该化合物吸收光谱的影响及其与 β 环糊精的作用。结果表明 ,pH >7 0时 ,该化合物在溶液中主要以中性分子状态存在 ,当 3 8

Synthesis of 2-(4-Dimethylaminophenyl)-5-Fluoro-6-(Morpholin-4-yl)-1H-Benzimidazole and Its Spectroscopic Research

A new potential pharmaceutical compound, 2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole (4) was synthesized. The effect of the pH value of aqueous solution on the absorption spectrum of compound 4 and its interaction with beta-cyclodextrin (beta-CD) were investigated by UV-Vis spectrum, steady-state fluorescence and time-resolved spectroscopic measurements. The results indicate that compound 4 mainly exists in neutral molecular state when pH value of the aqueous phase is above 7.0. In the pH range from 7.0 to 3.8 the neutral molecular state and protonated univalent cationic form coexist. As the pH value decreases, the content of univalent cationic form increases. When 2.76 < pH < 3.8, the protonated univalent cationic form is the predominant species. With further decrease of the pH value, the univalent cation is protonated by another H+ to form a bivalent cation, and both univalent and bivalent cations coexist in the solution. The steady-state fluorescence and time-resolved spectroscopic measurements revealed that compound 4 is a sensitive molecular probe. The interaction of compound 4 and beta-CD is very strong. The guest:host ratio of inclusion complex between compound 4 and beta-CD formed in the aqueous solution (pH = 9.50) is 1:1, and the association constant was determined to be (1.02 +/- 0.04) x 10(3) mol x L(-1).