8-羟基喹啉-7-醛的合成改进及其光谱性质

目的改进Reimer—Tiemann反应合成8-羟基喹啉-7-醛的实验方法，使其操作更方便，并提高产率。方法32mLCHCl3（0．4mol）滴加到100g35％～40％NaOH（1mol）水溶液和8-羟基喹啉（0．1mol）CH3CH2OH溶液体系中，65～70℃回流4h后，用0．1mol／LHCl酸化至PH5．0～5．5，可得到粗产物。再采用硅胶色谱柱分离，以V石油醚：V乙酸乙酯=40：1的混合溶剂作为洗脱剂，得橙红色结晶，然后用CHCl3重结晶得淡橙色针状晶体，真空干燥，可得产品3．1g。结果采用优化的实验方法合成了8-羟基喹啉-7-醛，产率为18％，熔点178℃，并利用红外光谱、质谱和核磁共振波谱对目标产物进行了结构表征，而且报道了其紫外和荧光光谱性质。结论改进了8-羟基喹啉-7-醛的合成方法，得到了目标产物，使实验操作方便易行，且提高了产率。

Improvement of synthesis of 8-hydroxyquinoline-7-carboxaldehyde and its spectral properties

Aim. To improve the method for synthesizing 8-hydroxyquinoline-7-carboxaldehyde, operating easily and higher yield by the Reimer-Tiemann reaction. Methods 32 mL CHCl3 （0.4 mol） was dropped into the system of 100 g 35%-40% NaOH （1 mol） aqueous and 14.5 g （0.1 mol） 8- hydroxyquinoline ethanol solution, refluxed at 65-70 ℃ for 4 h, the crude product was obtained after acidified at pH 5.0-5.5 by 0.1 mol/L HCl. A salmon pink crystal was separated and obtained by silica gel chromatographic column （eluent, VPetroleum ：V ethyl acetate = 40 ： 1）. Then, recrystallized with CHCla, 3. 1 g pale-orange needle crystal was obtained by vacuum drying apparatus. Results 8- hydroxyquinoline-7-carboxaldehyde was sythesized by the optimized method and the yield is up to 18%, the product＇s m. p. 178 ℃, it was characterized by IR, NMR and MS. Its spectral properties including ultraviolet-visible spectrum and fluorescence spectrum were reported. Conclusion The synthesis method of 8-hydroxyquinoline-7-carboxaldehyde was improved. The improved method operates easily and the yield is higher.