Hypoiodite, Haloform reaction

Several reported kinetic studies shed light on the various steps in the Haloform reaction. Bartlett showed in 1934 that the reaction of acetone with strong alkaline solutions of hypobromite and hypoiodite involves enolization of acetone as the ratedetermining step, but the rate of the same reaction with alkaline hypochlorite involves as the slow step reaction of acetone enol with hypochlorite.15 Likewise, the mechanism of the iodoform reaction and its optimization for quantitative analysis have received much scrutiny16 including studies of acetone-1-C-l4 7 and deuterated acetone18 for isotope... 

The aqueous base cleavage of a trifluoromethyl group from a lumazine hydrate is known,62 and the rupture of ring D of 3-benzy 1-O-estrone with hypoiodite to afford the corresponding tricyclic diacid (75% yield) has been reported.63 Indeed, over the years the iodoform version of the Haloform reaction has undergone extensive improvements64 and has seen applications in quantitative analysis65... 

Sodium hypobromite and sodium hypoiodite solutions react in an analogous manner and yield bromoform (CHBrj) and iodoform (CHI,) respectively. The smooth production of the trihalomethanes by the use of the appropriate hypohalides is termed the haloform reaction. It is applicable to all compounds containing the —COCH3 group or which yield a substance containing this group by oxidation (e.gr., acetaldehyde from ethyl alcohol). Iodoform is a stable, crystalline, yellow solid, m.p. 119°, with a characteristic odour it is only sparingly soluble in water and hence will separate, even in very minute quantity, from an aqueous solution and can easUy be identified by m.p. and mixed m.p. determinations. 

Undecanoic acid may be obtained from the product of part (g) by use of the haloform reaction followed by treatment with acid. Upon the addition of iodine and sodium hydroxide (to form sodium hypoiodite, NaOT), methyl... 

This sensitive test permits use of the readily available sodium hypochlorite in place of sodium hypoiodite for recognition of methyl carbonyl or methylcarbinol structures. It is useful also when detection of a haloform by infrared spectroscopy or gas-liquid chromatography is unsatisfactory, as may happen in certain reactions in which haloform-type cleavage occurs to a slight extent. ... 

The iodoform test is sometimes called the hypoiodite test because sodium hypoiodite is formed according to Equation 25.21. In more general terms, the reactions just described can be called the haloform test or the sodium hypohalite test... 

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