4-Bromo-2-chloro-6-iodoaniline

Setting Up Suspend 2.0 g of 4-bromo-2-chloro-6-iodoaniline in about 10 mL of absolute ethanol in the 250-mL round-bottom flask containing a stirbar. While stirring the mixture, add 4.0 mL of concentrated sulfuric acid dropwise. Equip the flask for heating under reflux. 

Consider the spectral data for 4-bromo-2-chloro-6-iodoaniline (Figs. 21.18 and 21.19). 

Discuss the differences observed in the IR and NMR spectra of 4-bromo-2-chloroaniline and 4-bromo-2-chloro-6-iodoaniline that are consistent with the formation of the latter in this procedure. 

Potassium dialkyl phosphite ions react rapidly with aryl iodides in liquid ammonia under irradiation to form diethyl esters of arylphosphonic acid in almost quantitative yields238. The photostimulated reaction of (EtO)2PO ions with 5-chloro-7-iodo-8-isopropoxyquinoline gave 70% of the substitution product with retention of the 5-chloro substituent239. The same nucleophile was formed in THF, and in a mixture of solvents (1 4 THF MeCN) reacts under irradiation with ArX (o-, ra-,/ -iodoanilines, 2-iodo, 3-iodo, 2-bromo and 3-bromopyridines and 3-bromoquinoline) rendering the substitution product in high yields (70-98%) (equation 130)240. 

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