【作者】 陈晓冬；

【导师】 叶志文；

【作者基本信息】 南京理工大学 ， 化学工艺， 2007， 硕士

【摘要】 本论文主要研究了间硝基甲苯液相催化加氢制备间甲苯胺并由间甲苯胺合成间甲酚和N—乙基间甲苯胺的反应工艺条件。催化加氢步骤中分别采用了Raney Ni、Ni-B非晶态合金和漆原镍三种催化剂。研究发现，采用Raney Ni为催化剂，NaOH与AI-Ni合金的质量比为1.7时制得的催化剂活性较高，在催化剂与原料质量比为0.6：10，甲醇作溶剂，反应时间为1h，反应压力1MPa，反应温度为80℃条件下间硝基甲苯转化率达100％：采用Ni-B催化剂，当BH₄^-／Ni²⁺=2左右制得的催化剂活性较高，在催化剂与原料质量比为3：10，无水乙醇作溶剂，反应时间为1h，反应压力1MPa，反应温度为100℃条件下间硝基甲苯转化率达100％，同时通过XRD、TEM对Ni-B非晶态合金进行表征；采用漆原镍为催化剂，展开剂为醋酸，锌粉与NiCl₂·6H₂O质量比为3∶2时制得的催化剂活性较高，在催化剂与原料质量比为5∶3，甲醇作溶剂，反应时间为1.5h，氢气流速15mL／min条件下间硝基甲苯转化率达100％，新鲜催化剂放置一周后活性才开始下降，催化剂可以循环使用10次，活性基本不变。三种催化剂是催化加氢的优良的催化剂，且各有特点。Raney Ni优点在于一次反应所需的用量较少，易自燃是它的不足；Ni-B非晶态合金不自燃，但反应条件的要求比Raney Ni高；温度低，常压反应是漆原镍最大优点，反应时间也适中，缺点是一次性需要加入的催化剂的量较大。合成间甲酚步骤中采用了重氮化、边水解边水蒸气蒸馏的反应工艺。通过单因素分析和正交实验得出较佳工艺条件，当H₂SO₄质量分数为25％，NaNO₂质量分数为30％，反应时间为35min，重氮化时NaNO₂滴加速度2mL／min，水解时重氮盐滴加速度9mL／min，水解时硫酸的浓度为4mol／L时，间甲酚收率达82.5％，经气相色谱分析其纯度达99.7％以上。合成N—乙基间甲苯胺步骤中，采用溴乙烷为烷化剂，在常压下进行反应。考察了反应物比例、时间和温度对N—乙基间甲苯胺选择性和间甲苯胺转化率的影响。可以得出最佳反应条件：间甲苯胺与溴乙烷物质的量的比为3：1，反应时间为8h，反应温度为50℃。在此条件下，间甲苯胺的转化率为80.6％，N—乙基间甲苯胺的选择性达84.2％，经气相色谱分析其纯度达99.6％以上。更多还原

【Abstract】 The m-toluidine was synthesized by catalytic hydrogenation fromm-nitrotoluene and then m-cresol and N-ethyl-m-toluidine were prepared fromm-toluidine.Three different catalysts were used in the process of catalytic hydrogenation. Ithas been found that the Raney Ni catalyst which was prepared on the condition thatm（NaOH）:m（Al-Ni）=1.7 has the best performance. Under the Condition thatm（catalyst）: m（m-nitrotoluene）=0.6:10, methanol as solvent, reaction time was lh,reaction pressure was 1MPa, reaction temperature was 80℃, the conversion ofm-nitrolotuene reached 100%. Ni-B amorphous alloy catalyst which was prepared onthe condition that BH₄^-/Ni²⁺=2 hasthe best performance. Under the condition thatm（catalyst）: m（m-nitrotoluene）=3:10, anhydrous ethanol as solvent, reaction timewas 1h, reaction pressure was 1MPa, reaction temperature was 100℃, theconversion of m-nitrolotuene reached 100%. And the Ni-B amorphous alloy wascharacterized by XRD and TEM. The urushibara nickel catalyst which was preparedon the condition that m（Zn）:m（NiCl₂·6H₂O）=3:2 and acetic acid as thedevelopingagent has the best performance. Under the condition that re（catalyst）:m（m-nitrotoluene）=5:3,methanol as solvent, reaction time was 1.5h and hydrogenvelocity was about 15 mL/min,the conversion of m-nitrolotuene reached 100%.Fresh catalyst’s performance just declined after a week’s time and the catalyst wasnot obviously deactivated after being used for 10 cycles.It has been found that the three catalysts were superior in catalytichydrogenation, but they have the different trait. Raney Ni was needed less at a timebut it tend to self-ignite; Ni-B amorphous alloy was more stability in air, but thereaction condition was severer than Raney Ni. Reaction in abnormal was the mostnotable advantage of urushibara nickel, and the reaction time was moderate. Theonly fault was that the urushibara nickel required much at a time.The m-cresol was synthesized from m-toluidine by diazotization and hydrolysiswith distillation. The better reaction condition is acquired by the single factoranalysis and orthogonal. Under the reaction condition thatω（H₂SO₄）=25%,ω（NaNO₂）=30%,and reaction time was 35 minutes, the dropwiserate of NaNO₂ in diazotization was 2mL/min,the dropwise rate of diazo salt inhydrolysis was 9mL/min,and the concentration of Sulfuric Acid when hydrolyzingwas 4mol/L,the yield of m-cresol is over 82.5% and the pureness is higher than 99.7%.The N-ethyl-m-toluidine was synthesized from m-toluidine under normalpressure, and used the bromethane as alkyl agent. Effects of proportion of reactant,reaction time and reaction temperature on selectivity of N-ethyl-m-toluidine andconversion of m-nitrotoluene were investigated. Under the optimum reactioncondition that n（m-toluidine）:n（bromethane）=3:1, reaction time was 8h and reactiontemperature was 50℃, the conversion of m-nitrotoluene was 80.6% and theselectivity of N-ethyl-m-toluidine reached 84.2%. the pureness is higher than 99.6%.更多还原