Iodine periodic acid

Treatment of commercially available and symmetrical 3,4,5-tri-methoxytoluene (37) with iodine, periodic acid, and acetic acid under the conditions of Suzuki19 results in the formation of symmetrical diiodide 38 in 93 % yield. Although only one of these newly introduced iodine atoms is present in intermediate 13, both play an important role in this synthesis. Selective monodemethylation of 38 with boron trichloride furnishes phenol 39 in 53% yield together with 13 % of a regioisomer. Evidently, one of the Lewis-basic iodine substituents coordinates with the Lewis-acidic boron trichloride and directs the cleavage of the adjacent methyl ether... 

Iodination (-Butyl hypoiodite. Iodine-periodic acid. Iodine monobromide, I-Iodohepta-fluoropropane. o-Phenylene phosphorochloridite. 

Iodine isocyanate, 161—163 Iodine—Periodic acid dihydrate, 163—164 3-Iodoazides, 160 Iodobenzene, li2, 154, 313 Iodobenzene dichloride, 142, 164-165 frans-/3-Iodocarbamates, 162... 

On the basis of experiments with myoinositol (50), it has been suggested that triose reductone should be oxidized by periodate to yield two molar equivalents of formic acid and one molar equivalent of carbon dioxide. However, it has been reported by two groups (1,29) that crystalline triose reductone is oxidized by two moles of periodic acid to give formic acid and glyoxylic acid, free iodine being liberated during the... 

Hesse and Mix (29) oxidized a relatively concentrated solution of triose reductone using limited amounts of free periodic acid. In these conditions, the iodic acid formed by the initial reduction of periodic acid could be further reduced and the reduction product could then, in turn, react with the remaining periodic acid and liberate iodine. Thus glyoxylic acid could be isolated from the oxidation mixture, as no periodate was available for its oxidation. 

Redox (reduction-oxidation) titrimetry is used primarily for nitrate detns. Five systems are in current use ferrous sulfate—dichromate, io dome trie, periodic acid oxidation (NaOH titrant), K permanganate, and titanous chloride-ferric ammonium sulfate. The ferrous sulfate— dichromate system is used for MNT DNT detns (Vol 2, C162-Lff Vol 6, F17-Rff Ref 17). In the iodometric procedure, the sample (ie, NG) is treated in a C02 atm with a satd soln of Mn chloride in coned HC1, the vol reaction products are bubbled thru a K iodide soln, and the liberated iodine is titrated with standard thiosulfate soln (Refs 1 17). The periodic... 

Iodinations can be carried out by mixtures of iodine and various oxidants such as periodic acid,26 I205,27 N02,28 and Ce(NH3)2(N03)6.29 A mixture of a cuprous iodide and a cupric salt can also effect iodination.30... 

Calculations derived from the measurement of final periodate consumption indicate the number of reactive groups and can often be interpreted to reveal the extent of overoxidation. Chemically, this determination involves the use of one of two general reactions. These are (a) the reduction of periodate and iodate to free iodine in acid solution, and (b) the reduction of periodate to iodate in neutral solution. 

Sandri (15) tested three titration methods with good results. One was titration with potassium bromate in the presence of potassium bromide and hydrochloric acid, using a starch-iodine end-point. Another was addition of excess periodic acid-potassium iodide with sodium... 

An ideal derivation would be via direct fluorination of Re and hydrolysis of ReF7 to perrhenic acid, especially since A/2f (Re207) has been determined by oxygen combustion of Re. However, ReF6 is the main fluorination product under normal conditions. It seems that further work on iodine fluorination to produce enhanced yields of the hepta-fluoride, and the hydrolysis of IF7 to periodic acid, is potentially the best route for improving the AHf(F( aq)) value. 

Periodic acid dihydrate, with iodine and durene to give iododurene, 51, 94 Phenols, from aryl methyl ethers, 53, 93 Phenylacetaldehyde, from 2-lithio-1,3,5-trithiane and benzyl bromide, 51, 43 Phenylacetic acid, bromination, 50, 31... 

Iodine is also given off to a small extent in dissolving the uranium metal in nitric acid, but larger amounts may be obtained on steam distillation after dissolution (5). Ruthenium is often removed from the fission products by distillation of the volatile tetroxide formed by oxidation with potassium permangate, sodium bismuthate, periodic acid (38) etc. The distillation goes readily and gives a product of good purity. 

Several oxidized compounds of iodine have been reported at various times. No doubt many of them are mixtures of iodic or periodic acids or anhydrides with iodine, etc. For example, there is (1) N. A. E. Millon s 8 oxyde soushypoiodique, Ik>019, t.e. I,0,.4Ia0a, formed as a yellow powder by the action of sulphuric acid on iodic acid. Millon regarded this oxide as hypoiodic anhydride, I40 or I09, mixed with a little iodous... 

Consequently the addition of the first mol. of KOH furnishes 515 Cals. the second, 21"44 Cals. the third, 3"15 Cals. and the fourth and fifth, 2-3 Cals. The mean of the first two values is 13"195, corresponding with the normal value for strongly ionized acids. This is said to be a chance result. J. Thomsen infers that periodic acid is dibasic, and writes the formula I04H3(0H)2 or better still tetrabasic I2OgH6(OH)i, and he writes the formula—oxygen quadrivalent, iodine univalent—... 

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