| M-fluorobenzaldehyde is an important medication raw material, which can beused for the syhthesis of some new type compounds antibiotic of ketone's, themedicine of cure high blood pressure, and some diminish inflammation medicines.The article stated the synthesis of the m-fluorobenzaldehyde with the raw material ofm-aminotoluene. First, m-aminotoluene was applied to prepare m-fiuorotoluene byBalz-Schemann reaction with sodium nitrite and sodium fiuoroborate, thenm-fluorobenzaldehyde was achieved by liquid phase oxidation of m-fluorotoluene.In order to improve the traditional craftwork of Balz-Schemann reaction, chloroformwas added as solvent to ease the whole reaction effectively. The optimum conditionswere obtained by the analysis of several parameters: the ratio of m-aminotoluene andhydrochloric acid was 1:2.5(mole ratio based on), the amount of sodium nitrite was1.05 times of theoretical value, the ratio of tetrafluoroborates and chloroform wasabout 1:3(mass ratio based on). Under these conditions, the yield came to 69.2ï¼…, thepurity came to 99.6ï¼…. The article told two catalyst systems for the liquid phaseoxidation of m-fluorotoluene, NHPI/MnCl2 catalyst system andCo(OAc)2/MnSO4/KBr catalyst system. The optimum conditions were obtained bythe analysis of several parameters. Under the optimum conditions, the conversion ofm-fiuorotoluene came to 33.4ï¼…, the selectivity came to 46.3ï¼…, and the yield was15.5ï¼…. It speculated on the mechanism of Co(OAc)2/MnSO4/KBr catalyst system. Thestructure of the compounds was identified by GC-MS, IR and 1HNMR. |
PDF Full Text Request