Preparation of para -Aminophenol from Nitrobenzene through Bamberger Rearrangement Using a Mixture of Heterogeneous and Homogeneous Acid Catalysts

Roxan Joncour (1) , Amadéo Ferreira , Nicolas Duguet (1) , Marc Lemaire (1)

1 CASYEN - Catalyse Synthèse et Environnement

The direct preparation of para-aminophenol (PAP) from nitrobenzene (NB) through Bamberger rearrangement was studied in a biphasic medium using a mixture of NbOx/SiO2 and H2SO4 as an acid catalyst. After optimization of the reaction parameters, PAP was obtained with 85–88% selectivity that represents a 10% selectivity improvement compared to sulfuric acid alone. The optimized conditions were implemented in a scale-up reaction, and PAP was isolated in 84% yield (based on the recovered starting material) with 97% HPLC purity. Overall, this process requires less sulfuric acid than the traditional process, leading to a drastic reduction of the saline waste.

Domains: Organic chemistry; Catalysis

Roxan Joncour, Amadéo Ferreira, Nicolas Duguet, Marc Lemaire. Preparation of para -Aminophenol from Nitrobenzene through Bamberger Rearrangement Using a Mixture of Heterogeneous and Homogeneous Acid Catalysts. Organic Process Research and Development, 2018, 22 (3), pp.312-320. ⟨10.1021/acs.oprd.7b00354⟩. ⟨hal-02128573⟩