General Description
3,4-Difluoroaniline (3,4-DFA) was degraded, under aerobic conditions, by
Pseudomonas fluorescens.
Synthesis
The general procedure for the synthesis of 3,4-difluoroaniline from 3,4-difluoronitrobenzene was as follows: 200.0 g of 3,4-difluoronitrobenzene, 600.0 mL of toluene and 12.0 g of Pd/C catalyst were added to an autoclave at 25 °C to 35 °C. Hydrogen was passed into the reaction system, keeping the hydrogen pressure between 2.0 and 6.0 kg/cm2, and the reaction was carried out at 25 °C to 35 °C for 3 to 4 hours. The progress of the reaction was monitored by thin layer chromatography (TLC) to ensure complete reaction. Upon completion of the reaction, the reaction mixture was sequentially depressurized and unloaded, filtered through a Hyflow bed, and the filter cake was washed with 200.0 mL of toluene. The filtrate was collected and vacuum distilled at less than 50 °C to remove the solvent. Finally, 152.0 g of crude 3,4-difluoroaniline was obtained in 93.8% yield and 95.85% purity by high performance liquid chromatography (HPLC).
References
[1] Patent: WO2015/68171, 2015, A1. Location in patent: Page/Page column 9; 16
[2] Tetrahedron Letters, 2010, vol. 51, # 5, p. 786 - 789
[3] Bioorganic and Medicinal Chemistry Letters, 2016, vol. 26, # 2, p. 613 - 617
[4] ChemPlusChem, 2018, vol. 83, # 5, p. 375 - 382
[5] Synthesis, 2001, # 1, p. 81 - 84