Synthesis
The general procedure for the synthesis of 3,3'-oxydiphenylamine from 3-iodoaniline and 3-aminophenol was as follows: 3-aminophenol (6.0 g, 54.8 mmol), 3-iodoaniline (10.0 g, 45.7 mmol), pyridine carboxylic acid (0.56 g, 4.6 mmol), cuprous iodide (I) and potassium phosphate (19.4 g, 91 mmol). DMSO (100 mL) was added as solvent and the reaction mixture was degassed by blowing in nitrogen for 1 hour. Subsequently, the reaction flask was placed in a preheated 80 °C oil bath and the reaction was stirred for 15 hours. After completion of the reaction, the mixture was cooled to room temperature. The reaction mixture was poured into 150 mL of water and extracted with ethyl acetate (3 x 50 mL). The organic phases were combined and washed sequentially with 50 mL of water and 50 mL of brine, dried and the solvent evaporated. The crude product was purified by silica gel column chromatography, eluting first with 80/20 (v/v) hexane/ethyl acetate solvent mixture and then with 50/50 (v/v) hexane/ethyl acetate solvent mixture to give 7.2 g (79% yield) of 3,3'-oxydiphenylamine as a white solid. The structure of the product was confirmed by GC/MS and NMR.
References
[1] Angewandte Chemie - International Edition, 2013, vol. 52, # 2, p. 650 - 654
[2] Angew. Chem., 2013, vol. 125, # 2, p. 678 - 682,5
[3] Patent: US9461254, 2016, B2. Location in patent: Page/Page column 195-196
[4] Journal of the American Chemical Society, 2009, vol. 131, # 47, p. 17423 - 17429
