4-溴-5-硝基-1,8-萘酐的合成工艺改进

Improved Synthesis of 4-Bromo-5-Nitro-1,8-Naphthalene Anhydride

摘要:

摘要：以苊为原料，NaBr/CeCl3.7H2O/H2O2为溴化试剂，得到5-溴苊，再用Al(NO3)3.9H2O/CH3COOH硝化，得到4-溴-5-硝基苊，进一步以醋酸钴/醋酸锰/N-羟基邻苯二甲酰亚胺/氧气为氧化剂，制备得到萘酰亚胺类荧光染料的重要中间体4-溴-5-硝基-1,8-萘酐。考察了原料配比、反应温度、时间以及溶剂对反应收率的影响，优选的最佳反应条件为：溴化反应温度25 ℃，反应时间3h，物质的量之比为n（苊）∶n（七水氯化铈）∶n（溴化钠）= 2∶1∶2.4，收率86.4%；硝化反应温度45 ℃，反应时间8h，物质的量之比为n（5-溴苊）∶n（九水硝酸铝）= 1∶1.2，收率88.4%；氧化反应温度110 ℃，反应时间5h，物质的量之比为n（醋酸钴）∶n（醋酸锰）∶n（N-羟基邻苯二甲酰亚胺）∶n（4-溴-5-硝基苊）= 1.2∶0.5∶1.2∶10，收率72.3%。同时进行了初步放大实验，研究结果表明，反应扩大5~20倍后仍具有较好的收率和效果。采用该方法制备目标产物，具有原料廉价易得，反应过程温和、环保、收率高和易于工业化的特点。

Abstract:

Abstract: Using acenaphthene as raw material and NaBr/CeCl3.7H2O/H2O2 as bromination reagent, 5-bromoacenaphthene was obtained. Then it was nitrated with Al(NO3)3.9H2O/CH3COOH to synthesize 4-bromo-5-nitroacenaphthene. Finally, using cobalt acetate/manganese acetate/N-Hydroxyphthalimide (NHPI)/oxygen as oxidant, 4-bromo-5-nitro-1,8-naphthalene anhydride was prepared, which is an important intermediate of naphthalimide fluorescent dyes. The effects of raw material ratio, reaction temperature, reaction time, and solvent on the reaction yield were explored, and the optimal reaction conditions were obtained. For the bromination reaction, the temperature was 25 ℃, the reaction time was 3 h, the ratio of the amount of substances of acenaphthene, cerium chloride heptahydrate, and sodium bromide was 2∶1∶2.4, and the yield was 86.4%. For the nitration reaction, the temperature was 45 ℃, the reaction time was 8 h, the ratio of the amount of substances of 5-bromoacenaphthene, Al(NO3)3.9H2O was 1∶1.2, and the yield was 88.4%. For the oxidation reaction, the temperature was 110 ℃, the reaction time was 5 h, the ratio of the amount of substances of cobalt acetate, Manganese acetate, NHPI and 4-bromo-5-nitroacenaphthene was 1.2∶0.5∶1.2∶10, and the yield was 72.3%. A preliminary scale-up experiment was conducted by using this method. The reaction yield was still high after the reaction was expanded by 5-20 times. This method has the characteristics of cheap and readily available raw materials, mild and environmentally friendly reaction process, high product yield, and easy industrialization.