| Using chitosan as raw material, the ionic liquids bonded on chitosan derivatives(IL-b-CS) were synthesized by the reaction of ionic liquids with chitosan. The catalytic performance of IL-b-CS on the N-hydroxyl alkylation reaction of aromatic amine and ethylene carbonate was studied. The study not only provides a new idea and method for the modification of chitosan, but also provides a new type catalyst for N-hydroxy alkylation reaction of aromatic amine with ethylene carbonate. So the study has some academic significance and potential application value. 1. Preparation, characterization and catalytic performance of methyl imidazole bromide bonded on chitosan derivatives(1) Methyl imidazole bromide bonded on chitosan(10 k Da) was synthesized in isopropyl alcohol-water system. The results showed that the degree of substitution of 3-(4-bromobutane)-1-methyl imidazolium bromide bonded on chitosan(BBMIB-b-CS) is the highest and arrives at 38.2%.(2) 3-(4-Bromobutane)-1-methyl imidazolium bromide bonded on chitosan(10 k Da) was synthesized in both isopropyl alcohol-water and water system, respectively. The results show that the degree of substitution in the water system is higher than in the isopropyl alcohol-water system, and arrives at 45.7%.(3) 3-(4-Bromobutane)-1-methyl imidazolium bromide bonded on chitosan(10 k Da and 200 k Da) were synthesized in water system. The results show that the degree of substitution about 10 k Da chitosan(45.7%) is higher than 200 k Da chitosan(42.4%).(4) Using BBMIB-b-CS as catalyst, the optimum catalytic condition on the N-hydroxyl alkylation reaction of aromatic amine and ethylene carbonate under the free solvent was as follows: naniline = 5.375 mmol, naniline:nethylene carbonate: nBBMIB group in BBMIB-b-CS = 1:2:0.06, 150℃ for 5 h, the conversion of aniline is 83.7%, the total yield of N-hydroxy alkylation product is 83.7%. Under the optimum catalytic conditions, the N-hydroxyl alkylation reaction about the other aromatic amines with ethylene carbonate were investigated. 2. Preparation, characterization and catalytic performance of alkyl pyridine bromide bonded on chitosan derivatives(1) Alkyl pyridine bromide bonded on chitosan(200 k Da) was synthesized in water system. The result showed that the degree of substitution about N-(4-bromobutane) pyridine bromide bonded on chitosan(BPBr-b-CS) is the highest and arrives at 25.0%.(2) Using BPBr-b-CS as catalyst, the best catalytic condition on the N-hydroxyl alkylation reaction of aromatic amine and ethylene carbonate under the free solvent was as follows: naniline = 5.375 mmol, naniline:nethylene carbonate:nBPBr group in BPBr-b-CS = 1:4:0.03, 150℃ for 6 h, the conversion of aniline is 91.0%, the total yield of N-hydroxy alkylation product is 85.1%. Under the optimum catalytic conditions, the N-hydroxyl alkylation reaction about the other aromatic amines with ethylene carbonate were investigated. 3. Preparation, characterization and catalytic performance of 1-butyl-4-formylpyridin-1-ium bromide bonded on chitosan derivatives(1) 1-Butyl-4-formylpyridin-1-ium bromide bonded on chitosan(200 k Da, BFPy Br-b-CS) was synthesized in water system, and the degree of substitution is 50.0%.(2) Using BFPy Br-b-CS as catalyst, the best catalytic condition on the N-hydroxyl alkylation reaction of aromatic amine and ethylene carbonate under the free solvent was as follows: naniline = 5.375 mmol, naniline:nethylene carbonate:nBFPy Br group in BFPy Br-b-CS = 1:4:0:06, 150℃ for 5 h, the conversion rate of aniline is up to 74.2%, the total yield of N-hydroxy alkylation product can reach 74.2%. Under the optimum catalytic conditions, the N-hydroxyl alkylation reaction about the other aromatic amines with ethylene carbonate were investigated.4. Under the optimum catalytic conditions, the N-hydroxyl alkylation reaction about the other aromatic amines with ethylene carbonate were investigated. The results show that, aromatic amines with electron-giving group can give better results; aromatic amines with electron-withdrawing group give fewer products. |
