Synthesis of arylamine compound

Abstract

Arylamine compound is prepared with aromatic nitro compound and through reaction in organic solvent at normal pressure in the presence of CO and water by using Se as catalyst and alkali as cocatalyst. The said aromatic nitro compound may have substituent radical in the phenyl radical and the substituent radical may be one or several electron donating and / or accepting group. The reaction conditions include the molar ratio between aromatic nitro compound and water of 1 to 1-1000; molar amount of Se is 0.1-100% of the aromatic nitro compound; molar amount of alkali is 0-400 % of the aromatic nitro compound; the weight ratio between aromatic nitro compound and solvent of 1 to 2-1000; reaction time of 1-36 hr; and reaction temperature of 20-120 deg.c.

Description

technical field [0001] The invention relates to a method for synthesizing aromatic amine compounds, in particular to a method for synthesizing aromatic amine compounds through selenium catalytic reduction of aromatic nitro compounds by using carbon monoxide and water under normal pressure. Background technique [0002] Aromatic amines, as a large class of important organic synthesis intermediates and raw materials, are widely used in medicine, pesticides, dyes and other fields. At present, the vast majority of aromatic amines are produced through the reduction of aromatic nitro compounds, and the number of relevant documents is huge. The reduction methods of nitro compounds used in industrialization mainly include the following: iron filings reduction, alkali sulfide reduction, Electrolytic reduction and catalytic hydrogenation reduction. Although the iron filings method and the soda sulfide method have wide adaptability, simple process, and reasonable technical economy, th...

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Problems solved by technology

Although the iron filings method and the soda sulfide method have wide adaptability, simple process, and reasonable technical economy, they are seriously polluted to the environment and have been gradually eliminated; the electrolysis method has high yield, easy operation, and environmental friendliness, but it consumes a lot of energy and is now widely used. It is used in laboratory synthesis and semi-industrial production; the catalytic hydrogenation method has large output and high product quality, and has obvious advantages in solving environmental pollution problems. Therefore, this method has become the mainstream in industry, but this method requires the use of excellent catalysts. The cost is high and the selectivity is poor. It is difficult to prepare from this method for many aromatic amines containing sensitive groups such as halogens and carbonyls.

In addition, there are reduction methods using hydrazine under the action of catalysts and metal hydride reduction methods, but they are only suitable for the reduction of special aromatic nitro compounds, and the cost is high, so they are not universal

In recent years, a reaction using carbon monoxide as a reducing agent to reduce aromatic nitro compounds has attracted people's interest due to its high selectivity to nitro groups (Tafesh A M, Weiguny J.A Review of the Selecivity Catalytic Reduction of Aromatic Nitro Compounds into Aromatic Amines Isocyanates, Carbamates and UreasUsing CO.J Chem Rev, 1996, 96: 2035-2052) but the reaction noble metal catalyst systems involved are somewhat complicated, and some have high cost, and are not the most favorable industrialized method

It has been reported that the selenium / carbon monoxide / water system was used to reduce aromatic nitro compounds to aromatic amines at a lower reaction temperature (80°C) (T Miyata, K Kondo, S Murai, THirashima and N Sonoda. Selenium-Catalyzed Reduction of Aromatic NitroCompounds to Amines by CO / H2O in the Presence of Triethylamine.AngewChem Int Ed Engl, 1980, 19(12): 1008), the yield is moderate to good, but triethylamine must be used as a cocatalyst

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