萘并吡喃的合成工艺改进及其光致变色性能

Process Improvement on the Synthesis of Naphthopyran and Its Photochromic Property

4,4'-二甲氧基二苯甲酮与乙炔钠经亲核加成反应制得1,1-二(4-甲氧基苯基)-2-丙炔-1-醇(2);以4,4'-二甲基二苯甲酮为原料,经3步反应制得中间体5-羟基-3,9-二甲基-苯并芴-7-酮(6);6与2经脱水反应合成了萘并吡喃(7),总收率16.3%,其结构经1H NMR和IR确证。采用UV-Vis研究了7的光致变色性能。结果表明:7的二甲基亚砜溶液(1.0×10-4mol·L-1)在可见光区呈无色,经过254 nm紫外光照射后呈蓝色,停止紫外光照射一段时间后溶液变回无色。随着光照时间的延长,吸光度呈上升趋势;反复进行紫外光的照射,吸光度变化不明显,表明7具有良好的抗疲劳性。

1,1-Di（ 4-methoxyphenyl）-2-propargyl-1-alcohol（ 2） was obtained by nucleophilic addition reaction of 4,4＇-dimethoxybenzophenoe with sodium acetylide. 5-Hydroxy-3,9-dimethylbenzofluorene-7-ketone（ 6） was obtained by a three-step reaction,using 4,4＇-dimethylbenzophenone as material. Naphthopyran（ 7） was synthesized by dehydration of 6 with 2. The total yield was 16. 3%. The structure was confirmed by1 H NMR and IR. The photochromic property of 7 was investigated by UVVis. The results showed that 7 in DMSO（ 1. 0 × 10^- 4mol·L^- 1） presented colorless in the region of visible. While it presented blue color if exposed to irradiation of 254 nm UV. The solution returned to be colorless when stopping irradiation for a while. If the illumination time prelonged,the absorbance rised. Though repeated UV radiation,there was not big difference with the absorbance. 7 exhibited good fatigue resistance.