Preparation Of O-Aminobenzotrifluoride

The paper reviews the exploration and the improvement for the preparation ofortho-aminobenzotrifluoride from benzotrifluoride. After consulting several pieces ofpatents and literatures, in this paper with benzotrifluoride as the staring material, thethree-process to prepare ortho-aminobenzotrifluoride was studied, which waschlorination, nitration, and hydrogenation. At the same time optimal processconditions and methods for purifying the product and recycling resolvent andtriethylamine were also present. MS confirmed the product.By parameters and orthogonal test, the effect of reaction time, reactiontemperature, catalysis dosage and chlorine dosage on the yield ofmeta-chlorobenzotrifluoride was studied, the optimized conditions for reaction wereobtained. Under the optimized conditions, the yield of ortho-aminobenzotrifluoride isover 74%.During the nitration of chlorinated mixture, By the orthogonal test the effect ofreaction time, reaction temperature, nitro-sulfuric acid dosage, the rate of sulfuric acidand nitric acid on the yield of 2-nitro-5-chlorobenzotrifluoride was studied. Theoptimized conditions for reaction were obtained. By the monofactorial experiments,the technological conditions of the nitration of dichloro-trifluoromethylbenzenes wereoptimized.In the liquid-phase hydrogenation of nitrifying mixture, four elements Raney Nishows excellent catalytic activity and strength, compared with many kinds of catalyst.The effect of Raney Ni dosage, reaction temperature, reaction time and resolventdosage on the yield of the ortho-aminobenzotrifluoride was studied, and then theoptimal process conditions were given.In the process of the after-treatment of hydrogenated product, with theimprovement of equipment, the yield of the ortho-aminobenzotrifluoride wasadvanced from 45% to over 95%. The hydrogenation product is distilled and rectifiedunder vacuum, the purity of ortho-aminobenzotrifluoride is 99.4%, while repeatabilityof recovered solvent and recovered triethylamine used in hydrogenation was II南京工业大学硕士论文 2004 年 5 月excellent.Moreover, the amplifying trials were run under the optimal technologicalconditions were practical and their yield were stable. The amplifying project whichpower of production is 100 of one year has been established.