Synthesis
General procedure for the synthesis of 5-iodosalicylaldehyde from salicylaldehyde: To a stirred solution of salicylaldehyde (1 mmol) in dichloromethane (CH2Cl2) or 1,2-dichloroethane ((CH2Cl)2) (0.1 M) was added triphenylphosphorane bis(trifluoromethylsulfonyl)imide (Ph3PAuNTf2) (0.025 mmol, 19 mg; if toluene-ligated Ph3PAuNTf2 complex, the ratio was 2:1), followed by the addition of N-iodosuccinimide (NIS) (1.1 mmol, 248 mg). The reaction mixture was stirred at room temperature or reacted under reflux conditions until complete conversion of salicylaldehyde was confirmed by thin layer chromatography (TLC) monitoring. Upon completion of the reaction, the solvent was evaporated under reduced pressure and the resulting crude product was purified by fast column chromatography using different ratios of hexane and ethyl acetate (EtOAc) as eluents to finally obtain purified 5-iodosalicylaldehyde.
References
[1] Journal of Organic Chemistry, 2015, vol. 80, # 9, p. 4306 - 4312
[2] Synlett, 2014, vol. 25, # 3, p. 399 - 402
[3] European Journal of Organic Chemistry, 2016, vol. 2016, # 12, p. 2177 - 2186
[4] Angewandte Chemie - International Edition, 2007, vol. 46, # 4, p. 572 - 575
[5] Chemistry - A European Journal, 2013, vol. 19, # 7, p. 2442 - 2449
