4-Bromo-2-chlorotoluene was synthesized from 4-bromo-2-nitrotoluene by reduction to give 5-bromo-2- methylaniline, which was subjected to diazotization and Sandmeyer reaction with an overall yield of 68%. As an improv...4-Bromo-2-chlorotoluene was synthesized from 4-bromo-2-nitrotoluene by reduction to give 5-bromo-2- methylaniline, which was subjected to diazotization and Sandmeyer reaction with an overall yield of 68%. As an improvement on the diazotization-Sandmeyer reaction, cuprous chloride was added before sodium nitrite.展开更多
4-Chloro-2-iodotoluene was synthesized from 4-chloro-2-nitrotoluene by reduction to give 4-chloro-2-aminotoluene methylaniline followed by substitution of diazonium group of the latter by iodo in 29% overall yield.
以邻卤代苯胺和水合氯醛、盐酸羟胺为原料,通过Sandmeyer异亚硝基乙酰替苯胺合成法制备得7-卤代靛红,再经硼氢化钠/三氟化硼乙醚体系还原制备得7-卤代吲哚。考察了酰胺化反应温度和反应时间、成环反应温度、还原体系种类及还原剂用量对...以邻卤代苯胺和水合氯醛、盐酸羟胺为原料,通过Sandmeyer异亚硝基乙酰替苯胺合成法制备得7-卤代靛红,再经硼氢化钠/三氟化硼乙醚体系还原制备得7-卤代吲哚。考察了酰胺化反应温度和反应时间、成环反应温度、还原体系种类及还原剂用量对反应收率的影响,所有产物结构均通过~1H NMR、^(13) C NMR和元素分析等进行了表征。结果表明,制备7-氟吲哚、7-溴吲哚、7-氯吲哚时,较佳的酰胺化反应温度和反应时间分别为回流10min、80℃4h和80℃3h,较佳的成环反应温度分别为80℃、85℃和80℃,较优的还原体系为硼氢化钠/三氟化硼乙醚体系,较优的还原剂用量为n(硼氢化钠)∶n(三氟化硼乙醚)∶n(7-卤代靛红)=3.0∶2.25∶1。该工艺具有成本低、反应条件温和、收率较高,操作简便等优点,适合批量制备7-卤代吲哚。展开更多
文摘4-Bromo-2-chlorotoluene was synthesized from 4-bromo-2-nitrotoluene by reduction to give 5-bromo-2- methylaniline, which was subjected to diazotization and Sandmeyer reaction with an overall yield of 68%. As an improvement on the diazotization-Sandmeyer reaction, cuprous chloride was added before sodium nitrite.
文摘4-Chloro-2-iodotoluene was synthesized from 4-chloro-2-nitrotoluene by reduction to give 4-chloro-2-aminotoluene methylaniline followed by substitution of diazonium group of the latter by iodo in 29% overall yield.
文摘以邻卤代苯胺和水合氯醛、盐酸羟胺为原料,通过Sandmeyer异亚硝基乙酰替苯胺合成法制备得7-卤代靛红,再经硼氢化钠/三氟化硼乙醚体系还原制备得7-卤代吲哚。考察了酰胺化反应温度和反应时间、成环反应温度、还原体系种类及还原剂用量对反应收率的影响,所有产物结构均通过~1H NMR、^(13) C NMR和元素分析等进行了表征。结果表明,制备7-氟吲哚、7-溴吲哚、7-氯吲哚时,较佳的酰胺化反应温度和反应时间分别为回流10min、80℃4h和80℃3h,较佳的成环反应温度分别为80℃、85℃和80℃,较优的还原体系为硼氢化钠/三氟化硼乙醚体系,较优的还原剂用量为n(硼氢化钠)∶n(三氟化硼乙醚)∶n(7-卤代靛红)=3.0∶2.25∶1。该工艺具有成本低、反应条件温和、收率较高,操作简便等优点,适合批量制备7-卤代吲哚。