This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4...This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4]arenes were obtained as main product respectively by diazo-coupling in different molar ratio to calix[4]arene in non-aqueous solution at 0-5 degrees.展开更多
Five novel azo calix[4]arenes were reported. The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution. Mono-, bis-, tris- and tetrakis(p-formylphenyl)azo calix[4]arenes (including p...Five novel azo calix[4]arenes were reported. The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution. Mono-, bis-, tris- and tetrakis(p-formylphenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arene (1) under pH=7.58.5 at 05 ℃. All (p-formylphenyl)azo calix[4]arenes were characterized by 1H NMR, 13C NMR, IR, MS (ESIMS) spectroscopies and elemental analysis.展开更多
A novel method for the preparation of chromogenic calixarenes with azo groups was reported. p-Substituted (-NO 2, -CH 3, -Cl) anilines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition. F...A novel method for the preparation of chromogenic calixarenes with azo groups was reported. p-Substituted (-NO 2, -CH 3, -Cl) anilines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition. Fifteen mono-, bis-, tris- and tetrakis(p-substituted phenyl)azo calixarenes (including pro^xi^mal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calixarenes (1) under pH= 7.5- 9.0 in non-aqueous solution at 0-5 ℃. 1H NMR and 13C NMR spectra of (p-substituted phenyl)azo calix^arenes indicated that they existed in cone conformation in solution.展开更多
An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0...An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0-5 ℃, solvent： water） within a short reaction time （1 h）. A plausible substitution reaction mechanism by phenol-ketone resonance was proposed.展开更多
文摘This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4]arenes were obtained as main product respectively by diazo-coupling in different molar ratio to calix[4]arene in non-aqueous solution at 0-5 degrees.
基金Project supported by the National Natural Science Foundation of China (No. 90101018) and the Center of Materials Analysis of Nanjing University.
文摘Five novel azo calix[4]arenes were reported. The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution. Mono-, bis-, tris- and tetrakis(p-formylphenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arene (1) under pH=7.58.5 at 05 ℃. All (p-formylphenyl)azo calix[4]arenes were characterized by 1H NMR, 13C NMR, IR, MS (ESIMS) spectroscopies and elemental analysis.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .90 10 10 18)andtheFoundationofStateKeyLaboratoryofBioorganicandNaturalProductsChemistryinShanghaiInstituteofOrganicChemistry ,ChineseAcademyofSciences .
文摘A novel method for the preparation of chromogenic calixarenes with azo groups was reported. p-Substituted (-NO 2, -CH 3, -Cl) anilines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition. Fifteen mono-, bis-, tris- and tetrakis(p-substituted phenyl)azo calixarenes (including pro^xi^mal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calixarenes (1) under pH= 7.5- 9.0 in non-aqueous solution at 0-5 ℃. 1H NMR and 13C NMR spectra of (p-substituted phenyl)azo calix^arenes indicated that they existed in cone conformation in solution.
基金supported by the National Natural Science Foundation for Young Scholar of China(No.21276042)the National Science and Technology Pillar Program(No. 2013BAF08B06)Jiaogai Foundation of DUT(No.JGXM201224)
文摘An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0-5 ℃, solvent： water） within a short reaction time （1 h）. A plausible substitution reaction mechanism by phenol-ketone resonance was proposed.
