Ether hydriodic

Cleavage of ethers with hydriodic acid. Aliphatic ethers suflFer fission when boiled with constant boiling point hydriodic acid ... 

Reflux 1 ml. of the ether with 5 ml. of freshly distilled, constant boiling point hydriodic acid (Section 11,49,2), b.p. 126-128°, for 2-3 hours. Add 10 ml. of water, distil and collect about 7 ml. of liquid. Decolourise the distillate by the addition of a httle sodium bisulphite, and separate the two layers by means of a dropper pipette (Fig. 11,27,1). Determine the b.p. of the resulting iodide by the Siwoloboff method (Section 11,12) and prepare a crystalline derivative (Section 111,42). 

Dialkyl peroxides can be reduced to the corresponding alcohols and/or ethers using a variety of reducing agents, some of which, eg, hydriodic acid, have been used for analysis. 

Hydroxyisophthalic acid has been prepared by oxidizing 2-hydroxy-3-methylbenzoic acid with lead dioxide, by cleaving the ether group of 2-methoxyisophthalic acid with hydriodic acid, and by hydrolyzing 2-iodoisophthalic acid with alcoholic sodium hydroxide. ... 

There still remains to be settled the point of attachment of the a-aminopropionic acid side-chain in leucenol. As the latter is unaffected by boiling hydrobromic or hydriodic acid, an ether linkage at C in 3-hydroxypyridone-4 is unlikely and as the side-chain is eliminated by either pyrolysis or the action of alkali C for the location, as suggested by Kostermanns see mimosine below) is improbable. The balance of evidence seems to be in favour of attachment to the N-atom and additional data supporting this view have been provided by Adams and Jones. ... 

A solution of 0.46 g of the diazoketone in 100 ml of chloroform is shaken with 22 ml of 48 % hydriodic acid for 1.5 min. After the addition of 400 ml of chloroform, the organic layer is washed successively with a saturated solution of potassium iodide, with a solution of sodium thiosulfate and with water. After drying, evaporation of the solvent yields 0.44 g of a product which is chromatographed over 10 g of alumina (diam. of column 1.0 cm). Elution with benzene (400 ml) and benzene-ether (9 1) (200 ml) gives 0.32 g of 3jS,5) ,19-trihydroxypregnan-20-one 3,19-diacetate (yield 76%) mp 96-99°. 

Note There appear to be no recent examples of this reaction with simple alkoxy substrates (perhaps because normal aliphatic ethers need quite vigorous treatment, such as boiling hydriodic acid), but so-called isopropylidenedioxy derivatives (that undergo facile hydrolysis) have been used in this way. l-[2,3-(Isopropylidenedioxy)propyl]-3-methyl-2(17/)-quinoxalinone (165) gave l-(2,3-dihydroxypropyl)-3-methyl-2(l//)-quinoxahnone (70% AcOH, reflux, 2 h 35% homologs likewise). ... 

Ethers are unaffected by sodium and by acetyl (or benzoyl) chloride. Both the purely aliphatic ethers e.g., di-n-butyl ether (C4H, )30 and the mixed aliphatic - aromatic ethers (e.g., anisole C3HSOCH3) are encountered in Solubility Group V the purely aromatic ethers e.g., diphenyl ether (C,Hj)20 are generally insoluble in concentrated sulphuric acid and are found in Solubility Group VI. The purely aliphatic ethers are very inert and their final identification may, of necessity, depend upon their physical properties (b.p., density and/or refractive index). Ethers do, however, suffer fission when heated with excess of 67 per cent, hydriodic acid, but the reaction is generally only of value for the characterisation of symmetrical ethers (R = R ) ... 

The mixed aliphatic - aromatic ethers are somewhat more reactive in addition to cleavage by strong hydriodic acid and also by constant b.p. hydrobromic acid in acetic acid solution into phenols and alkyl halides, they may be bromi-nated, nitrated and converted into sulphonamides (Section IV,106,2). 

Demethylation of a phenolic ether by hydriodic acid, 22, 91 Desiccator, vacuum, dumb-bell type, 23,105... 

Hydracrylic acid, see p-Propiolactone Hydrazobenzene, see Aniline Hydriodic acid, see Methyl iodide Hydrobromic acid, see Bromodichloromethane, Bromoform, Methyl bromide, Metobromuron Hydrochloric acid, see Alachlor. Aldrin, Benzyl chloride, a-BHC, p-BHC, Bis (2-chloroethyl) ether, Bis(2-chloroisopropyl) ether, Bromacil. Bromodichloromethane, Carbon tetrachloride, Chloroethane, Chloroform, o-Chloronitrobenzene. Chloropicrin, Chloroprene, p-Chloronitrobenzene, 2,4-D, see Dalanon-sodium. p.p -DDD, p,p -DDT, Dicamba. 1,1-Dichloroethane, 1,1-Dichloroethylene, fratts-l,2-Dichloroethylene, s/m-Dichloromethyl ether, 2.3-Dichloronitrobenzene. 3.4-Dichloronitrobenzene. 1,2-Dichloropropane, cis-1,3-... 

The tetraiodide is slightly soluble in acetone and in ethanol (about 1 gm PoI4/liter) but is insoluble in dilute mineral acids and in ethers, aliphatic acids and hydrocarbons. It is slowly hydrolyzed by water and by concentrated alkali, the white product presumably being a basic iodide, and is decomposed by chlorine, hypochlorite, nitrite, and hot concentrated nitric acid. It does not react with ammonia gas but is reduced to the metal on heating in hydrogen sulfide. Suspensions of the tetraiodide in 0.1 N hydriodic acid are unaffected by hydrazine or sulfur dioxide, even on boiling, and there is no evidence for a diiodide. 

Diiodobutane has been prepared in 51% yield by the reaction of phosphorus, iodine, and tetrahydrofuran. It has also been prepared by the reaction of hydriodic acid with phenoxy-butyl iodide and with the diisoamyl ether of 1,4-butancdiol. ... 

Alkenes from p-oxygenated selenidesS /J-Phenylseleno lactones, ethers, and alcohols are converted into alkenes on treatment with ClSi(CHj)j and Nal in C HiCN. Hydriodic acid (formed by inadvertent hydrolysis) may play a role this acid cun effect this reaction, but in lower yield. This elimination thus reverses cyclo-(unclionali/ations induced by C6H5ScX (cf Na-NH3, 9, 26), and in addition provides a stereospecific route to alkenes by way of/l-hydroxv selenides. lixnmplc ... 

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