ABBX, A Highly Active Trivalent Iodine Compound for Oxidation Reactions

1-Acetoxy-5-bromo-1,2-benziodoxol-3(1H)-one (1, ABBX) is a highly active trivalent iodine compound developed by Togo et al.¹⁾ 1 oxidizes aliphatic primary and secondary alcohols to the corresponding aldehydes and ketones in good yields. 5-Bromo-2-iodobenzoic acid, formed as a co-product of this reaction, can be recovered by acidification of the aqueous layer. 1 has chemically similar activity to “Super DIB” (ANBX) which was introduced in TCIMAIL number157 p.8, and has more solubility in organic solvents than Super DIB.^1,2)

Typical Procedure (oxidation of 4-methylbenzyl alcohol to 4-methylbenzaldehyde): To a solution of 4-methylbenzyl alcohol (1.0 mmol, 122.1 mg) in CHCl₃ (4 mL) is added ABBX (2.0 mmol, 767.7 mg). The mixture is stirred at 60 °C for 24 h. After the reaction is completed, the reaction mixture is added to aq. NaHCO₃ (10 mL). The aqueous layer is extracted with CHCl₃ (3 × 10 mL), and the organic layer is dried over Na₂SO₄. The filtrate is concentrated under reduced pressure to give 4-methylbenzaldehyde (108.0 mg, 90% yield) with 90% purity. The aqueous layer is acidified (pH ca. 2) with 1 M aq. HCl (15 mL) and the obtained mixture is filtered to afford 2-iodo-5-bromobenzoic acid (593 mg, 91%).