Acids hydriodic acid

Iodoform2 from Acetone.—Teeple3 mentions a method by which almost the theoretical yield of iodoform can be obtained by the electrolysis of a potassium-iodide solution in the presence of acetone. No diaphragm is required, the essential feature being the gradual addition of a substance like hydrochloric acid, hydriodic acid, or, better, iodine, to neutralize the excess of potassium hydroxide as fast as it is formed. The tempera-, ture is kept below 25°, and the electrolyte thoroughly stirred in fact the same current conditions should be observed as in the case of chloroform above mentioned, the aim in this case also being to maintain the conditions always favorable for the production of a maximum amount of hypoiodite. 

DOT UN 1787/UN2197 mf HI mw 127.91 PROP Acrid gas colorless when freshly made, but rapidly turns yellowish or brown on exposure to light or air. Mp —50.8°, bp -35.38° 5 atm, d 5.66 g/L 0°. Keep protected from light and air, preferably not above 3°. When heated, decomp to H2 and I2. Aq solns are strongly acid. Attacks natural rubber. Misc with water and ale. SYNS ANHYDROUS HYDRIODIC ACID HYDRIODIC ACID, solution (UN 1787) (DOT) HYDROGEN IODIDE HYDROGEN IODIDE, anhydrous (UN 2197) pOT)... 

Hydrochloric acid Hydrobromic acid Hydriodic acid... 

Quinazolinones 1 bearing a methoxy substituent in the benzene ring, readily obtained by cyclization of the appropriate precursors (cf. Section 6.3.1.1.1.), are transformed into the corresponding hydroxyquinazolinones 2 on treatment with hydrobromic acid, - hydriodic acid, aluminum trichloride,or boron tribromide. Similarly, quinazoline-2,4-diamines bearing a methoxy group at position 6 or 8 are demethylated with boron tribro-mide in dichloromethane, sodium methanethiolate in dimethylacetamide or by pyridini-um hydrochloride fusion at 200... 

Hydriodic Acid Hydrobromic Acid hydriodic acid 10 23 <360 <360 T1 u u... 

Ethers Aiuminum bromide. Aluminum chloride. Boron tribromide. Boron trichloride. Diborane. Diphenyl phosphide, lithium salt. Hydrobromic acid. Hydriodic acid. Lithium bromide. Lithium bromide-BFt etherate. Lithium diphenyl. Methylmagnesium iodide. Pyridine hydrochloride. Sodium iodide. Sodium-Potassium alloy. Triphenylphosphine dibromide. 

Hexagonal prisms mp 58° dj 2.9508 bp 260. Very sol in water so] in sulfuric acid insol in ammonia dec in alcohol. Very deliquescent. Reduced by hydrobromic acid, hydriodic acid, hydrogen sulfide, hydroxylamine hydrochloride, phenyl hydrazine, formic acid, oxalic acid, malonic acid, pyruvic acid, acetyl chloride, and several metals. 

Quinone is reduced in cold aqueous solution to quinol by sulphurous acid, hydriodic acid, and other reducing agents —... 

Hydriodic Acid Hydriodic acid (H I) is very unstable and decomposes very rapidly on exposure to light. It is thus frequently prepared in situ, from sodium iodide and phosphoric or sulfuric acid. It is often used in solution in glacial acetic acid, and reacts with alcohols to give the corresponding halides. 

Hydrochloric acid-hydriodic acid elutriant. Prepared by mixing 1 ml of hydriodic acid stock solution with 9 ml of concentrated hydrochloric acid. The precipitate formed by hydrazine is removed by centrifuging the supernatant then is saturated with gaseous hydrogen chloride. The reagent must be prepared every few days because it decomposes easily. 

Skelly, N.E. Separation of aliphatic and aromatic acids, aromatic sulfonates, quaternary ammonium compounds, and chelating agents on a reversed-phase column without ion pairing, J.Chromatogr.ScL, 2003, 41, 22-25. [nonoxynol-9 citric add benzenesulfonic acid phthsilic acid hydrobromic acid nitrUotriacetic acid oxalic acid nitric acid hydriodic acid glycolic acid formic add nitrous add cyanuric acid lactic acid acetic acid NTA benzalkonium EDTA]... 

Boric acid Chlorosulfonic acid Chromic acid 30-70% Chromium trioxide Chromosulfuric acid Chromosulfuric acid <30% Ruorosilic acid Fluorosulfonic acid Hydriodic acid 30-70% Hydrobromic acid Hydrobromic acid 30-70% Hydrochloric acid 37% Hydrochloric acid <30%... 

A number of dilute chemical solutions attack tin metal slowly, with consequent corrosion. Among these are aluminium chloride, aluminium potassium alum, ammonium sulphate, hydrochloric acid, hydrobromic acid, hydriodic acid, fluorine, chlorine, bromine, iodine, iron(III) chloride, potassium carbonate, potassium hydroxide, silver nitrate, zinc chloride, glycerol and maleic acid. ... 

Hydriodic Acid hydriodic acid, hydrogen, idodide soiution technicai 23 0-360 2 Not resistant rapid attack stress " cracking irreversibie damage ... 

The base pyridine removes the hydriodic acid formed. The endpoint occurs when the brown colour of free iodine is seen, i.e. when all the water has been used up. This method is widely used. 

In the first reaction, sulphur may be filtered off, leaving only hydriodic acid. 

Properties—Hydrogen iodide is a colourless gas. It is very soluble in water and fumes in moist air (cf. hydrogen chloride), to give hydriodic acid. Its solution forms a constant boiling mixture (cf. hydrochloric and hydrobromic acids). Because it attacks mercury so readily, hydrogen iodide is difficult to study as a gas, but the dissociation equilibrium has been investigated. 

Hence hydrogen iodide cannot be produced by the reaction of sulphuric acid with an iodide. Hydriodic acid is slowly oxidised by air (more rapidly in light) liberating iodine ... 

E values. Nitric acid attacks mercury, oxidising it to Hg (aq) when the acid is concentrated and in excess, and to Hgf (aq) when mercury is in excess and the acid dilute. Hydriodic acid Hl(aq) attacks mercury, because mercury(Il) readily forms iodo-complexes (see below, p. 438). 

Principle. A definite amount of the substance ca. 25 mg.) is weighed out and transferred to the reaction bulb of the apparatus where it is decomposed by refluxing with constant-boiling hydriodic acid, the essential reaction being ... 

Hydrogen iodide. This gas may be conveniently prepared by allowing a solution of two parts of iodine in one part of hydriodic acid, sp. gr. 1 7 (for preparation, see Section 11,49,2), to drop on to excess of red phosphorus. The evolution of hydrogen iodide takes place in the cold when the evolution of gas slackens considerably, the mixture should be gently warmed. 

Hydriodic acid. A 1-5 litre three-necked flask is charged with a mixture of 480 g. of iodine and 600 ml. of water. The central aperture is fitted with a stopper carrying an efficient mechanical stirrer leading... 

By the slow distillation of the alcohol with constant boiling point (57 per cent) hydriodic acid, for example ... 

Mix 30 g. (38 ml.) of iaopropyl alcohol with 450 g. (265 ml.) of constant boiling point hydriodic acid (57 per cent.) (Section 11,49,2) in a 500 ml. distilling flask, attach a condenser for downward distillation, and distil slowly (1-2 drops per second) from an air bath (compare Fig. II, 5, 3). When about half the liquid has passed over, stop the distillation. Separate the lower layer of crude iodide (80 g.). Redistil the aqueous layer and thus recover a further 5 g. of iodide from the flrst quarter of the distillate (1). Wash the combined iodides with an equal volume of concentrated hydrochloric acid, then, successively, with water, 5 per cent, sodium carbonate solution, and water. Dry with anhydrous calcium chloride and distil. The isopropyl iodide distils constantly at 89°. 

Allyl Iodide. Use 29 g. (34 ml.) of allyl alcohol and 340 g. (200 ml.) of 57 per cent, hydriodic acid 84 g. of crude iodide are obtained. Upon adding 29 g. (34 ml.) of allyl alcohol to the combined residue in the flask and the aqueous layer and distilling as before, a further 72 g. of crude allyl iodide may be isolated. B.p. 99-101° (mainly 100°). The compound is very sensitive to light the distillation should therefore be conducted in a darkened room and preferably in the presence of a little silver powder. 

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). 

A good 3ueld of 5-iodo-2-aminotoluene may be obtained by intimately mixing o-toluidine hydrochloride, iodine and calcium carbonate, and then adding water to the mixture. The liberated hydriodic acid reacts at once with the Calcium carbonate and the lij driodide of the base is not formed. 

It is believed that the red phosphorus is the true reducing agent and the iodine (or iodide) functions as a hydrogen carrier. This proc ure replaces the obsolete method of heating with red phosphorus and concentrated hydriodic acid in a sealed tube. 

Hydrolysis of the azlactone leads to the acylaminooinnamic acid the latter may be be reduced catal3rtlcally (Adams PtOj catalyst 40 lb. p.s.i.) and then hydrolysed by hydrochloric acid to the amino acid. Alternatively, the azlactone (say, of a-benzylaminocinnamic acid) may undergo reduction and cleavage with phosphorus, hydriodic acid and acetic anhydride directly to the a-amino acid (d/ p phenylalanine). 

---