A New Pd-Based Catalytic System for the Reductive Carbonylation of Nitrobenzene to Form N-(4-hydroxyphenyl)acetamide Selectively in One Pot

N-(4-hydroxyphenyl)acetamide (commonly named paracetamol or acetaminophen) is a target molecule for many industries that produce chemicals for pharmaceutical applications. The industrial processes, however, use multistep procedures with low overall yield and/or severe drawbacks and problems in terms of sustainability. In the present paper, a one-pot synthesis is proposed based on the reductive carbonylation of nitrobenzene catalyzed by Pd(II)-complexes. Usually, such a reaction leads to a mixture of different products, including aniline, 4-aminophenol and 1,3-diphenylurea. However, the selectivity towards the possible products strongly depends by the ligands on the Pd(II)-catalyst, but also by the nature of the solvent. According to this, we have found that when the reaction was carried out in dilute acetic acid as a solvent, the [PdCl2(dppb)] catalyst precursor leads in one pot to N-(4-hydroxyphenyl)acetamide. Under optimized reaction conditions, it was possible to produce N-(4-hydroxyphenyl)acetamide with a 85 mol % of selectivity in ca. 5 h

Trifluoroacetic Acid Hydroxylamine System as Organocatalyst Reagent in a One-Pot Salt Free Process for the Synthesis of Caprolactam and Amides of Industrial Interest

Abstract In this work we studied the reactivity of the Trifuoroacetic acid hydroxylamine system in the one step salt free synthesis of amides from ketones. A particular regards was paid to the caprolactam synthesis because of its industrial relevance. Synthesis, reactivity and characterization of the hydroxylamine trifuoroacetate is given. Fast oximation reaction of several ketones was gained at room temperature (1 h of reaction quantitative conversion for several ketones). In the same reactor, by raising the temperature at 383 K, the Beckmann rearrangement of the so obtained oximes is easily accomplished in the presence of three equivalent of TFA. The possibility of obtaining the trifuoroacetate of the hydroxylamine with a modifed nitric acid hydrogenation reactions was verifed, too. Reuse of solvent and trifuoroacetic acid is easily achieved by distillation

Surfactant Aided Reductive Carbonylation of Nitrobenzene inWater Catalyzed by Pd Complexes

The catalytic carbonylation of nitroarenes is a field of high interest from a technological point of view, since provides an environmentally benign route to a number of important industrial products, such as isocyanates, carbamates, ureas, azoarenes and azoxyarenes, amines, amides, oximes and several types of heterocyclic compounds. The reductive carbonylation of nitrobenzene in water carried out by using Pd(II)-solvable catalyst precursors, leads to aniline, as major product. In the present paper we propose the micellar catalytic reductive carbonylation of nitrobenzene in water. The Pd(II) catalyst precursors tested are synthesized by using cheaper commercial insolvable ligands, such as triphenylphosphine (PPh3), 1,3- bis(diphenylphosphino)propane (dppp) and 1, 10-phenantroline (phen). The influence on the conversion and on the selectivity of such precursors has been evaluated in combination with commercial anionic (SDS), cationic (TBAB) and non ionic (Triton X 100) surfactants. We have found that all the Pd(II) complexes tested are efficiently dissolved in each O/W emulsions but the conversion is strongly influenced by the nature of ligand. By using Pd(OAc)2(PPh3)2, high selectivity towards azo- and azo-oxybenzene has been obtained. The influence of some reaction parameters has been further evaluated and optimized

Recommendation for future actions in research and developments

The Sustainable Chemistry Issue Team has been active within the OECD Environment Health and Safety Programme since 1998 and has held many meetings in Germany and in Italy. Although Italy has organized two meetings (Venice, 1998 and 2001) and has an excellent scientific and technological background in the field, the coordination among research, academy and industry, necessary to undertake actions among the leader countries of this area, has not yet been activated. At this end the University Ca’ Foscari of Venice, in collaboration with the Istituto Superiore di Sanità (ISS – Italian Institute for Health) that co-ordinates in Italy the OECD activities in the framework of the Environment, Health and Safety Programme, has organized this Workshop aimed to the establishment of the Italian network on green and sustainable chemistry. The connection with EU achievements and with the recently instituted OECD Green Growth Knowledge Platform has been highlighted. The first part of the Workshop has addressed European activities carried out in this field. OECD, EuCheMS, UNESCO have participated. The second part, organised in collaboration with pertinent Italian ministries, universities, public research institutes and industries has highlighted the different point of views inherent to the sustainable development and in particular the state of art of the green and sustainable chemistry in Italy in connection with its international perspectives