Beckmann rearrangement mechanism of cyclohexanone oxime, based on the characteristic of self-catalyzed reaction and polymorphism was proposed. According to the suggested mechanism, the basic approach was the rearrange...Beckmann rearrangement mechanism of cyclohexanone oxime, based on the characteristic of self-catalyzed reaction and polymorphism was proposed. According to the suggested mechanism, the basic approach was the rearrangement of OXH+ while the SO3 acts as dehydrating agent and OXSO3 can turn to CPLSO3 ultimately. Considering self-catalyzed reaction between OXSO3 and CPLH+, kinetic model for Beckmann rearrangement was established. Corresponding parameters were estimated by using float genetic algorithm （GA） and simulation results agree well with the experimental data below -19.3℃. Industrial equipment was simulated and analyzed. Effects of key process parameters such as molar ratio of sulfuric acid to oxime and circulation ratio on the residual oxime are also discussed. The results show that the caprolactam exists as CPLH+ finally in oleum and the minimum molecular ratio of sulfuric acid to oxime can be 0.5 theoretically.展开更多
为研究不同催化剂对Beckmann重排反应性能的影响,本研究以二苯甲酮为原料制备二苯甲酮肟,以H_3PO_4-Ac_2O(1∶2,V/V)为催化剂利用Beckmann重排制得苯甲酰苯胺。通过单因素试验和正交试验优化得到最佳的实验方案。结果表明10 m L H_3PO_4...为研究不同催化剂对Beckmann重排反应性能的影响,本研究以二苯甲酮为原料制备二苯甲酮肟,以H_3PO_4-Ac_2O(1∶2,V/V)为催化剂利用Beckmann重排制得苯甲酰苯胺。通过单因素试验和正交试验优化得到最佳的实验方案。结果表明10 m L H_3PO_4-Ac_2O,在125℃下反应20 min时,产物收率在92.6%。产物经红外光谱、核磁共振氢谱、高效液相色谱进行分析表征。同时采用高效液相色谱法,测得该化合物的纯度约为97.3%。展开更多
以二苯甲酮和盐酸羟胺为原料,在一定条件下制得二苯甲酮肟,通过三因素四水平正交试验(温度、催化剂、溶剂)的设计,探索重排反应的最佳条件,结果表明,在110℃下反应20 min,添加10 m L PPA,以乙醇作为溶剂,产率可达70%以上。以二苯甲酮肟...以二苯甲酮和盐酸羟胺为原料,在一定条件下制得二苯甲酮肟,通过三因素四水平正交试验(温度、催化剂、溶剂)的设计,探索重排反应的最佳条件,结果表明,在110℃下反应20 min,添加10 m L PPA,以乙醇作为溶剂,产率可达70%以上。以二苯甲酮肟作为研究对象,研究Beckmann重排反应的最优化条件,最后应用1H-NMR、13C-NMR核磁共振波谱、红外光谱等手段对制得的酮肟和酰胺进行分析表征。展开更多
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam.By strategically using the in situ generated Appel’s salt or Mitsunobu’s zwitterionic adduct as the de-hydrating agent,...The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam.By strategically using the in situ generated Appel’s salt or Mitsunobu’s zwitterionic adduct as the de-hydrating agent,a series of Beckmann rearrangement and following cascade reactions have been devel-oped herein.The protocol allows the conversion of various ketoximes into amide,thioamide,tetrazole and imide products in modular procedures.The generality and tolerance of functionalities of this method have been demonstrated.展开更多
Zirconia with high surface area (247 m 2/g) obtained by digesting sol gel of hydrous zirconia was used as a carrier of the B 2O 3/ZrO 2 catalyst for the gas phase Beckmann rearrangement of cyclohexanone oxime to form ...Zirconia with high surface area (247 m 2/g) obtained by digesting sol gel of hydrous zirconia was used as a carrier of the B 2O 3/ZrO 2 catalyst for the gas phase Beckmann rearrangement of cyclohexanone oxime to form caprolactam. Effects of boria loading and activation calcination temperature on the catalyst performance were investigated. The optimization of the boria loading and the calcination temperature leads to a highly stable and regenerable B 2O 3/ZrO 2 catalyst for the rearrangement reaction. When the boria loading is 26 9% and the catalyst is calcined at 600 ℃, the B 2O 3/ZrO 2 shows the best performance, and it has been one of the best solid catalysts for the gas phase Beckmann rearrangement so far.展开更多
基金Project(20233040) supported by the National Natural Science Foundation of China and SI NOPEC
文摘Beckmann rearrangement mechanism of cyclohexanone oxime, based on the characteristic of self-catalyzed reaction and polymorphism was proposed. According to the suggested mechanism, the basic approach was the rearrangement of OXH+ while the SO3 acts as dehydrating agent and OXSO3 can turn to CPLSO3 ultimately. Considering self-catalyzed reaction between OXSO3 and CPLH+, kinetic model for Beckmann rearrangement was established. Corresponding parameters were estimated by using float genetic algorithm （GA） and simulation results agree well with the experimental data below -19.3℃. Industrial equipment was simulated and analyzed. Effects of key process parameters such as molar ratio of sulfuric acid to oxime and circulation ratio on the residual oxime are also discussed. The results show that the caprolactam exists as CPLH+ finally in oleum and the minimum molecular ratio of sulfuric acid to oxime can be 0.5 theoretically.
文摘为研究不同催化剂对Beckmann重排反应性能的影响,本研究以二苯甲酮为原料制备二苯甲酮肟,以H_3PO_4-Ac_2O(1∶2,V/V)为催化剂利用Beckmann重排制得苯甲酰苯胺。通过单因素试验和正交试验优化得到最佳的实验方案。结果表明10 m L H_3PO_4-Ac_2O,在125℃下反应20 min时,产物收率在92.6%。产物经红外光谱、核磁共振氢谱、高效液相色谱进行分析表征。同时采用高效液相色谱法,测得该化合物的纯度约为97.3%。
文摘以二苯甲酮和盐酸羟胺为原料,在一定条件下制得二苯甲酮肟,通过三因素四水平正交试验(温度、催化剂、溶剂)的设计,探索重排反应的最佳条件,结果表明,在110℃下反应20 min,添加10 m L PPA,以乙醇作为溶剂,产率可达70%以上。以二苯甲酮肟作为研究对象,研究Beckmann重排反应的最优化条件,最后应用1H-NMR、13C-NMR核磁共振波谱、红外光谱等手段对制得的酮肟和酰胺进行分析表征。
基金supported by National Key Research and Development Project (No. 2021YFC2100100)National Natural Science Foundation of China (No. 21901123)+1 种基金Natural Science Foundation of Jiangsu Province (No. BK20190694)Jiangsu Specially Appointed Professor Plan
文摘The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam.By strategically using the in situ generated Appel’s salt or Mitsunobu’s zwitterionic adduct as the de-hydrating agent,a series of Beckmann rearrangement and following cascade reactions have been devel-oped herein.The protocol allows the conversion of various ketoximes into amide,thioamide,tetrazole and imide products in modular procedures.The generality and tolerance of functionalities of this method have been demonstrated.
文摘Zirconia with high surface area (247 m 2/g) obtained by digesting sol gel of hydrous zirconia was used as a carrier of the B 2O 3/ZrO 2 catalyst for the gas phase Beckmann rearrangement of cyclohexanone oxime to form caprolactam. Effects of boria loading and activation calcination temperature on the catalyst performance were investigated. The optimization of the boria loading and the calcination temperature leads to a highly stable and regenerable B 2O 3/ZrO 2 catalyst for the rearrangement reaction. When the boria loading is 26 9% and the catalyst is calcined at 600 ℃, the B 2O 3/ZrO 2 shows the best performance, and it has been one of the best solid catalysts for the gas phase Beckmann rearrangement so far.
