摘要
以红色基GL(邻硝基对甲苯胺)为原料,采用“高温”重氮化反应分别经Sandmeyer反应、还原反应和Schiemann反应可制得纯度≥99.9%(GC)的4-氯-3-氟甲苯和纯度≥99.0%(GC)的4-溴-3-氟甲苯,总收率分别为33.8%和33.9%。其中重氮化氯代反应的最佳反应条件为:反应温度50℃,反应时间2.5h,n(红色基GL):n(CuCl)=1:0.55,保温温度70℃;重氮化溴代反应的最佳条件为:反应温度50℃,反应时间4h,n (红色基GL):n(CuBr)=1:0.60,保温温度60℃。产物经IR和GC-MS验证符合预期结构。此“高温”重氮化法可扩大至中试生产。
4-Chloro-3-fluorotoluene and 4-bromo-3-fluorotoluene were synthesized from o-nitro-p-toluidine(Fast Red Base GL) , through diazo reaction at high temperature, Sandmeyer reaction,reduction and Schiemann reaction. The purity of 4-chloro-3-fluorotoluene and 4-bromo-3-fluorotoluene were 99.9% (GC) and ≥99.0% (GC), respectively, while the overall yield were 33.8% and 33. 9%, respectively. The optimal conditions for diazo-chlorination were: 50 ℃,reaction time 2.5 h, n(Fast Red Base GL ) : n(cuprous chloride)=1 : 0.55 and reaction temperature 70 ℃. The optimal conditions for diazo-bromization were: 50 ℃, reaction time 4 h, n(Fast Red Base GL ) : n(cuprous bromide)=1 : 0.60 and reaction temperature 60 ℃. The structures of the products were confirmed by IR and GC-MS. The high temperature diazo reaction could be scaled up.
出处
《精细石油化工》
CAS
CSCD
北大核心
2007年第1期39-43,共5页
Speciality Petrochemicals