METHOD FOR PREPARING AROMATIC AMINES BY REDUCTION OF CORRESPONDING NITRO-COMPOUNDS

摘要

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method for preparing aromatic amines, namely to preparing unsubstituted or N-methyl- substituted aromatic amines that are used in production of dyes, drugs, antioxidants and antidetonating additives to fuel and so on. Method for preparing aromatic amines involves the reduction reaction of corresponding nitro-compounds with methanol in vapor phase at elevated temperature in the presence of industrial copper-containing catalyst, for example, type "Virgon", or "S-40", or "NTK-10-7F" modified with nickel or palladium, or platinum and taken in the amount 0.3-10 wt.-%. Usually process is carried out at temperature 200-260 C, under atmosphere pressure and feeding rate of the parent liquid mixture of methanol with aromatic nitro-compound from 0.5 to 2.5 t^-1 and maintaining the ratio methanol/aromatic nitro- - compound in the parent mixture from 1:1 to 5:1. Proposed method ensures to enhance the total yield of aromatic amines up to 99.5%, output by product up to 0.4-1.3 g/g x h and safety of process due to exclusion of hydrogen and carrying out the process under atmosphere pressure. Method allows depending on ratio of used reagents to alternate ratios of synthesized N-methyl-substituted and unsubstituted aromatic amines. EFFECT: improved preparing method. 4 cl, 1 tbl