2-Methyl-4-methoxyaniline （MMA） was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The eff...2-Methyl-4-methoxyaniline （MMA） was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-（propyl-3-sulfonate）-3-methylimidazolium hydrosulfate （[HSO3-pmim][HSO4]） as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.展开更多
The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl...The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl）hydroxylamine increased from 71%to 90%when the reduction was carried out at 25℃under normal pressure of CO2.展开更多
Selective oxidation of o-nitrotoluene to onitrobenzaldehyde with metalloporphyrins as biomimetic catalysts was studied.The peripheral substituent around porphyrin rings and various process parameters of NaOH concentra...Selective oxidation of o-nitrotoluene to onitrobenzaldehyde with metalloporphyrins as biomimetic catalysts was studied.The peripheral substituent around porphyrin rings and various process parameters of NaOH concentration,reaction temperature,reaction time and oxygen pressure all affect the selectivity of onitrobenzaldehyde.Further,82.0%selectivity of onitrobenzaldehyde was achieved under the optimum conditions:1.0×10^(-5)mol·L^(-1)of T(p-NO_(2))PPFeCl catalyst,2.5 mol·L^(-1)of NaOH,0.2 mol·L^(-1)of o-nitrotoluene,45℃and 2.0 MPa for 6 h.展开更多
基金Supported by the National Natural Science Foundation of China （21106134） and the Natural Science Foundation of Zlaejlang Province （Y4100671）.
文摘2-Methyl-4-methoxyaniline （MMA） was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-（propyl-3-sulfonate）-3-methylimidazolium hydrosulfate （[HSO3-pmim][HSO4]） as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.
基金supported by the Doctoral Fund of Ministry of Education of China(No.20070141046)the Fund of Education Department of Liaoning Province(No.[2006]124)
文摘The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl）hydroxylamine increased from 71%to 90%when the reduction was carried out at 25℃under normal pressure of CO2.
基金supported by the Key Project of the Natural Science Foundation of Beijing(No.2061001)the National Natural Science Foundation of China(Grant Nos.20576005,20776003).
文摘Selective oxidation of o-nitrotoluene to onitrobenzaldehyde with metalloporphyrins as biomimetic catalysts was studied.The peripheral substituent around porphyrin rings and various process parameters of NaOH concentration,reaction temperature,reaction time and oxygen pressure all affect the selectivity of onitrobenzaldehyde.Further,82.0%selectivity of onitrobenzaldehyde was achieved under the optimum conditions:1.0×10^(-5)mol·L^(-1)of T(p-NO_(2))PPFeCl catalyst,2.5 mol·L^(-1)of NaOH,0.2 mol·L^(-1)of o-nitrotoluene,45℃and 2.0 MPa for 6 h.
