One stage preparation of Schiff’s bases from nitroarenes, aldehydes and carbon monoxide at presence of water

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2004-02, Vol.209 (1), p.69-73
• Main Authors: Macho, Vendelı́n, Králik, Milan, Hudec, Jozef, Cingelova, Jarmila
• Format: Article
• Language: English
• Subjects: Aldehydes; Carbon monoxide; Carbonylation condensation; Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Ketones; Nitroarenes; Nitrosoarenes; Poly-Schiff’s bases; Schiff’s bases; Sulphur based catalytic system; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Water
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2003.08.018

Using a sulfur-based catalytic system, nitroarenes, carbon monoxide and water react to the corresponding amines. In the presence of aldehydes, Schiff’s bases are formed. Applying nitrocarbonyl compounds, e.g. 4-nitrobenzaldehyde, polymeric substances are obtained, in which sulfur acts as a cross-linker. Results from one stage condensation reaction of nitroarenes (nitrobenzene, o-nitrotoluene, p-nitrotoluene, 4-chloro-1-nitrobenzene, 4-methoxy-1-nitrobenzene) or nitrosobenzene and carbonyl compounds (benzophenone, benzaldehyde, acetaldehyde) with carbon monoxide at the presence of water are presented. Schiff’s bases are formed by this reaction. High conversion of nitro- and nitroso-arenes and selectivity to Schiff’s bases up to 90% was observed with the sulphur based catalytic system (COS, or H 2S, + Et 3N+NH 4VO 3) at pressure 12 MPa of CO (measured at 25 °C) and the temperature range from 90 to 165 °C. A comparable reaction rate and conversion of nitro- and nitroso-arenes up to 99.8% was also reached (after 4 h, at 160 °C) with benzaldehyde using Pd/(PdCl 2+FeCl 3+Et 3N) system as a catalyst. Selectivity to the corresponding Schiff’s bases was 79–82%. Aromatic nitrocarbonyl compounds, which possess poly-Schiff’s bases, are formed at the temperature of 150±2 °C, pressure of CO 12 MPa at 25 °C and using sulphur base catalytic system. Sulphur based catalytic system was found to be very effective. Its low price and non-sensitivity to the common catalytic poisons makes it more advantageous than the other catalytic systems.