Studies On Selenium-catalyzed Reduction Of O- Chloronitrobenzene To O-chloroaniline

O-chloroaniline is a kind of important fine chemical intermediates. It is widely used in pesticide, dye, pharmaceutical and other fine chemical synthesis. It is generally used to the reduction of o-chloronitrobenzene with iron, sodium sulfide, or hydrazine hydrate. However, these reactions often accompany with dehalogenation reactions, and reduce the selectivity of o-chloroaniline.This paper imports Se/CO/H2O system to the reduction of o-chloronitrobenzene, which is a new method to prepare o-chloroaniline, compared with the traditional reduction.The system was used in high pressure condition to reduce o-chloronitrobenzene. First, the substrate was selected as the solvent itself in the method by optimizing the solvent. Then, the optimal reaction conditions were determined by a large number of condition experiments, orthogonal and paralleling validation experiments was maded. Finally, the catalyst test was tried.The system presented the high conversion rate in the reduction of o-chloronitrobenzene and inhibited the formation of dechlorination by-product. This paper is divided into four parts. The first part is literature review, mainly introduced the the application of o-chloroaniline and method of preparation. The second part introduces the process of the experiment. The third part, we do a lot of condition experiments and paralleling validation experiments to get optimum reaction conditions, and orthogonal experiment get main factors affecting reaction. The final part summons the whole work we didIn the condition of o-chloronitrobenzene 40 mmol, selenium 0.128 g, sodium acetate 0.84 g, water 20 mL, temperature 160℃, reaction time 3.5 hours ,conversion rate of o-chloronitrobenzene to o-chloroaniline reduction > 99%, without by-product generation.