苯乙烯喹啉衍生物的合成及其光谱性质

报道了一种苯乙烯基喹啉衍生物的合成新方法。将10 mmol苯胺溶于10 mL 6 mol·L~(-1)盐酸中,加热至100℃,搅拌下缓慢滴加丁烯醛(20 mmol)的甲苯溶液8 mL,100℃反应3 h生成中间体2-甲基喹啉;2-甲基喹啉(10 mmol)再同芳香醛(12 mmol)衍生物在冰醋酸(15 mL)中回流8 h合成八个苯乙烯喹啉衍生物,产率71%~88%,该方法操作简便、便于纯化、产率较高、环境友好。合成的衍生物进行MS,~1HNMR,IR结构表征,红外图谱在960~980 cm~(-1)间出现中等强度的吸收峰,核磁图谱中烯碳上氢的邻位偶合常数在12~18 Hz之问,表明结构中的碳碳双键为反式构型。测定了八个衍生物在CH_3OH,DMSO,THF和DMF等四种溶剂中的最大吸收波长,将最大吸收波长作激发波长,测定了其发射波长。结果表明:苯乙烯喹啉衍生物的最大吸收波长为325~376 nm,发射波长为367~477 nm,摩尔消光系数为1.738×10~4~4.578×10~4 L·mol~(-1)·cm~(-1)含甲氧基、羟基、苄基的衍生物的最大吸收波长和发射波长大于其他化合物。衍生物在不同溶剂中的最大吸收波长变化微弱,发射波长变化明显,表现为DMSODMFCH_3OHTHF,表明同一种化合物在非质子溶剂中的斯托克斯位移值大于质子溶剂。2-(3,4,5-三甲氧基)苯乙烯基喹啉(化合物Ⅱ)的荧光性质最好,斯托克斯位移值最大,有进一步研究的价值。

The Syntheses and Spectroscopic Properties of the Styryl Quinoline Derivatives

The simple method of the syntheses of the styrylquinoline derivatives was developed .The intermediate of 2-methylquinoline was synthesized from 10 mmol aniline and 20 mmol (E)-2-Butenal dissolved in 8 mL methylbenzene refluxing at 100 ℃ for 3 hours with 10 mL 6 M hydrochloric acid as catalyst .Eight derivatives were obtained in 15 mL glacial acetic acid using 2-methylquinoline (10 mmol) and aromatic aldehyde (12 mmol) as materials refluxing for 8 hours with a yield of 71％～88％ .The method is simple,high yield,easy purification and environment friendly .The structures of all derivatives were confirmed with MS,1HNM R and IR .The vicinal coupling constant of olefinic carbon hydrogen in 1H NMR is 12～18 Hz,and moderate strength absorption peaks appeared at 960～980 c m-1 in IR indicate that carbon-carbon double bond is transconfiguration .Maximum absorption wavelengths of eight products in CH3OH,DMSO,THF and DM F were measured,and emission wavelengths were measured using maximum absorption wavelengths as excitation wavelengths .It turned out that maximum absorption wavelengths among different solvents were 325～376 nm,and emission wavelengths were 367～477 nm .The molar extinction coefficients were within the range of 1738×104～4578×104 L·mol-1·cm-1 .The maximum absorption wavelengths and emission wavelengths of styryl quinoline derivatives with methoxyl,hydroxyl and benzyl group are greater than others .Among four solvents,t he maximum absorption wavelengths almost unchanged,however,the emission wave lengths varies significantly in the following order DMSO＞DMF＞CH3OH＞THF,which indicates the Stokes shift of one product at aprotic solvent is greater than pro tic solvent .2-(3,4,5-trimethoxyphenyl)styryl quinolone (Product Ⅱ) which shows the best fluorescence property and the highest Stokes shift value worth further studying .