2,2′-Dichlorohydrazobenzene(DHB) was prepared in two steps. o-Chloronitrobenzene( OCNB) was at first reduced to 2,2′-dichloroazoxybenzene(DOB) in aqueous medium using 2,3-dichloro-1,4-naphthaquinone(OCNQ) as catalys...2,2′-Dichlorohydrazobenzene(DHB) was prepared in two steps. o-Chloronitrobenzene( OCNB) was at first reduced to 2,2′-dichloroazoxybenzene(DOB) in aqueous medium using 2,3-dichloro-1,4-naphthaquinone(OCNQ) as catalyst with yield of 99.4%, mp 53～56 ℃; DOB was then reduced by formaldehyde to give DHB in aqueous alkaline methanol with yield of 76%, 49% higher than reported, mp 82～83.5 ℃. DHB could be rearranged to 3,3′-dichlorobenzidine in strong acidic medium with yield 91.8%, mp 132～ 134 ℃.展开更多
The new and rapid synthetic method for hydrazobenzene starting from azobenzene through ZnNH4CNS reduction.The optimum reaction conditions are that the molar ratio of azobenzene to zinc powder is 1∶15,the temper...The new and rapid synthetic method for hydrazobenzene starting from azobenzene through ZnNH4CNS reduction.The optimum reaction conditions are that the molar ratio of azobenzene to zinc powder is 1∶15,the temperature is 25℃,the consumption of saturated ammonium thiocyanate liquor is 10ml.The reaction duration is short(8min) yet giving excellent yields(94%).展开更多
应用离子交换膜法电解邻氯硝基苯合成2,2′-二氯氢化偶氮苯.讨论了电极活化条件、电流密度、电解液温度等因素对电解还原反应的影响.结果表明:在反应温度t=80℃,阴极、阳极电解液分别为10%和30%(by m ass)的NaOH溶液,电流密度4.2A/dm2...应用离子交换膜法电解邻氯硝基苯合成2,2′-二氯氢化偶氮苯.讨论了电极活化条件、电流密度、电解液温度等因素对电解还原反应的影响.结果表明:在反应温度t=80℃,阴极、阳极电解液分别为10%和30%(by m ass)的NaOH溶液,电流密度4.2A/dm2条件下电解,电流效率最高,可达73%,收率为83%.展开更多
文摘2,2′-Dichlorohydrazobenzene(DHB) was prepared in two steps. o-Chloronitrobenzene( OCNB) was at first reduced to 2,2′-dichloroazoxybenzene(DOB) in aqueous medium using 2,3-dichloro-1,4-naphthaquinone(OCNQ) as catalyst with yield of 99.4%, mp 53～56 ℃; DOB was then reduced by formaldehyde to give DHB in aqueous alkaline methanol with yield of 76%, 49% higher than reported, mp 82～83.5 ℃. DHB could be rearranged to 3,3′-dichlorobenzidine in strong acidic medium with yield 91.8%, mp 132～ 134 ℃.
文摘The new and rapid synthetic method for hydrazobenzene starting from azobenzene through ZnNH4CNS reduction.The optimum reaction conditions are that the molar ratio of azobenzene to zinc powder is 1∶15,the temperature is 25℃,the consumption of saturated ammonium thiocyanate liquor is 10ml.The reaction duration is short(8min) yet giving excellent yields(94%).
文摘应用离子交换膜法电解邻氯硝基苯合成2,2′-二氯氢化偶氮苯.讨论了电极活化条件、电流密度、电解液温度等因素对电解还原反应的影响.结果表明:在反应温度t=80℃,阴极、阳极电解液分别为10%和30%(by m ass)的NaOH溶液,电流密度4.2A/dm2条件下电解,电流效率最高,可达73%,收率为83%.
