|3-Iodoxybenzoic Acid: Handle With Care
Gary A. Cain
Chemical & Engineering News ( 01 July 2002) Vol. 80, No. 26, p. 4.
We wish to warn the chemical community of a serious shock sensitivity hazard associated with 3-iodoxybenzoic acid [64297-65-0], a reagent popularized by Derek Barton and coworkers [J. Chem. Soc., Perkin Trans. I, 8, 1947 (1982)] for preparing enones from ketones in the presence of catalytic diphenyl diselenide.
We recently prepared this reagent on a 200-g scale following the generic one-step procedure for iodoxybenzene given in the above reference using acetic acid and commercial bleach. After collecting the solid product in a Buchner fritted glass funnel, rinsing, and air drying, the compound was being transferred with a spoon into a bottle for storage when it suddenly exploded.
The funnel was destroyed, and glass fragments were propelled with such force to break several glass items in the vicinity. Fortunately, the operator received only minor cuts and skin/eye irritation as a result of wearing proper gloves, lab coat, and safety glasses, and was fine after prompt treatment.
While this compound was known to deflagrate at its melting point, 225°C [J. Labelled Compd. Radiopharm., 19, 1161 (1982)], its shock sensitivity has not been reported. Our incident prompts us to warn that 3-iodoxybenzoic acid, prepared according to the Barton reference above, presents a severe shock hazard, and utmost care is required for its handling. We cannot state with certainty whether the explosion was due to the compound itself or was perhaps initiated by residual bleach or other impurities.
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