间氟甲苯控制氧化合成间氟苯甲醛

【作者】 许昕；

【导师】 吕春绪； 李斌栋；

【作者基本信息】 南京理工大学 ， 应用化学， 2008， 硕士

【摘要】 间氟苯甲醛是重要的有机合成中间体,可广泛地应用于医药、农药、塑料添加剂等精细化学品的合成。本文通过采用不同的氧化剂氧化间氟甲苯合成间氟苯甲醛,重点研究了氧气,二氧化锰和三氧化二锰的氧化效果,分别研究了它们的氧化工艺条件以及固体氧化剂的循环利用,并初步探讨了它们的氧化机理。考察了Co/Mn/Br含水氧化体系对间氟苯甲醛产率的影响,当醋酸-水混合溶剂中水含量为10%时,产率最高为15.80%;二氧化锰氧化的最佳条件为:反应温度为90℃,硫酸质量浓度为70%,反应时间为6h,间氟甲苯与二氧化锰的摩尔比为1∶1.6,产率最佳值为56.02%;三氧化二锰氧化的最佳条件为:反应温度为50℃,硫酸质量浓度为70%,反应时间为8h,间氟甲苯与三氧化二锰的摩尔比为1∶2.4,产率最佳值为75.38%。二氧化锰氧化性较强,副产物较多,醛的选择性较低,而三氧化二锰具有很好的选择性。并对最终产物进行了气质、红外、核磁分析。废液硫酸和硫酸锰通过处理可以循环利用,在硫酸锰溶液中加入碳酸氢铵将其转化为碳酸锰,通过在370℃的马弗炉中灼烧6h得到二氧化锰,将二氧化锰在650℃下灼烧1h得到三氧化二锰。实现了固体氧化剂的绿色循环利用。更多还原

【Abstract】 m-Fluorobenzaldehyde was an important organic synthesis intermediate,and can be widely applied in fine chemicals synthesis,such as medicine,pesticides,plastics additives. This paper mainly introduced different oxidation methods,but oxygen,manganese dioxide and manganese sesquioxide were mainly studied.Oxidation conditions and the recycling of solid oxidation were studied.Their mechanisms were initially discussed.Co/Mn/Br catalyst system containing water,which was effect on the yield of m-fluorobenzaldehyde was studied.When the water content of the acetic acid-water mixed solvents was 10%,the yield was 15.80%.The optimum reaction conditions of manganese dioxide oxidation were as follows:the temperature was 90℃,the concentration of H₂SO₄ was 70%,the time was 6h,the molar ratio of m-fluorotoluene and manganese dioxide was 1:1.6, the yield was 56.02%.The optimum reaction conditions of manganese sesquioxide oxidation were as follows:the temperature was 50℃,the concentration of H₂SO₄ was 70%,the time was 8h,the molar ratio of m-fluorotoluene and manganese sesquioxide was 1:2.4,the yield was 75.38%.The oxidability of manganese dioxide was very strong,so the by-products were more,the selectivity of m-fluorobenzaldehyde was lower.Manganese sesquioxide had the good selectivity,m-Fluorobenzaldehyde was analyzed through GC-MS,IR,NMR.Waste H₂SO₄ and MnSO₄ can be handled through recycling.MnCO₃ was obtained by joining NH₄HCO₃ in MnSO₄,which was baked for 6h at 370℃,then translated into MnO₂. Mn₂O₃ was obtained by baking MnO₂ at 650℃for 1h.The solid oxidant recycling was achieved.更多还原