Graphene Oxide‐Immobilized Iron Porphyrin Catalysts for Efficient Synthesis of 5‐Bromo‐1,3‐Difluoro‐2‐Nitrobenzene

Abstract 5‐Bromo‐1,3‐difluoro‐2‐nitrobenzene is a key intermediate in drug synthesis. Therefore, the development of efficient and environmentally friendly synthesis methods is essential for its application in medicine. In this study, 5‐bromo‐1,3‐difluoro‐2‐nitrobenzene was successfully synthesized by catalyzing 4‐bromo‐2,6‐difluoroaniline. The reaction employed graphene‐supported tetra‐p‐aminophenyl porphyrin iron complex (GO‐FeTAPP) as the catalyst. Additionally, tert‐butylhydrogen peroxide (TBHP) was used as the oxidant, and dichloromethane (DCM) served as the solvent. The reaction conditions were maintained at room temperature for 24 h, and the overall yield was approximately 60% with a turnover frequency (TOF) of ≈ 5 h −1 . Compared to the tetra‐p‐aminophenylporphyrin iron (FeTAPP) catalytic system, the catalytic activity of GO‐FeTAPP was enhanced. The product yield was increased by 47%. Notably, this yield approaches the highest reported value in literature (60%) that was achieved using sodium perborate tetrahydrate as the catalyst. Importantly, our catalytic system required minimal catalyst loading, with a substrate‐to‐GO‐FeTAPP (FeTAPP basis) molar ratio of ≈ 200:1 ‐ significantly lower than that of the sodium perborate system. Furthermore, the GO‐FeTAPP catalyst demonstrated excellent stability and reusability, maintaining over 85% of its initial catalytic activity after five consecutive reaction cycles.