Synthesis
The general procedure for the synthesis of 2-iododiphenyl ether from 2-aminodiphenyl ether is as follows:
1. the intermediate Bn-2 (1 eq.) and p-toluenesulfonic acid monohydrate (PTSA-H2O, 72.5 g, 3 eq.) were dissolved in acetonitrile (224 mL, 1.3 M) under ice-bath conditions and cooled to 5 °C.
2. A solution of sodium nitrite (NaNO2, 41.7 g, 2 eq.) dissolved in 240 mL of water was added dropwise.
3. After the dropwise addition was completed, the reaction mixture was kept at 5°C for 1 hour to produce the diazonium salt.
4. The resulting diazonium salt solution was slowly added to a solution of potassium iodide (KI, 100 g, 2 eq.) dissolved in 300 mL of water.
5. Upon completion of the reaction, the residue was extracted with ethyl acetate (EtOAc) and the organic layers were combined.
6. The combined organic layers were washed with 10% sodium sulfite (Na2SO3) solution and dried with anhydrous sodium sulfate (Na2SO4).
7. After filtration, the organic layer was concentrated under reduced pressure to obtain the crude product.
8. The crude product was purified by silica gel column chromatography to obtain the target compound 2-iododiphenyl ether.
References
[1] Chemistry - A European Journal, 2014, vol. 20, # 39, p. 12553 - 12558
[2] Journal of the Indian Chemical Society, 2013, vol. 90, # 10, p. 1537 - 1555
[3] Chemistry - A European Journal, 2012, vol. 18, # 11, p. 3286 - 3291
[4] Patent: US2018/155312, 2018, A1. Location in patent: Paragraph 0087; 0093-0095
[5] Journal of the American Chemical Society, 2015, vol. 137, # 11, p. 3775 - 3778
