Hydrogen bromide sulphide

The catalysed -elimination of hydrogen bromide from 2-bromoethyl and 1,2-dibromoethyl sulphides, using 9.1.1 or 9.1.2, provides a convenient route to vinyl and alkynyl sulphides, respectively [17, 18], which, as their sulphoxides or sulphones, have considerable utility as dienophiles. Aryl vinyl ethers (>90%) have been obtained by analogous procedures from 2-chloroethyl ethers [19]. 

Hydrogen bromide, iodide and sulphide are oxidised to the corresponding elements, various reduction and hydrolytic products of the pyrosulphuryl chloride being formed at the same time. Phosphine also causes reduction of pyrosulphuryl chloride with production of sulphide of phosphorus.4... 

When arsenic trisulphide is exposed to dry hydrogen chloride or hydrogen bromide, it liquefies at the ordinary temperature and on heating complete volatilisation occurs.9 It is not readily attacked by halogen acids. When boiled with concentrated hydrochloric acid it is decomposed, but with great difficulty, and the hydrogen sulphide and arsenious chloride evolved reproduce arsenious sulphide in the receiver.10 A similar reaction occurs when heated with a chloride in the presence of concentrated sulphuric acid, but the decomposition is incomplete.11 The reaction is facilitated by the presence of cuprous chloride or ferric chloride. Only a slight reaction is observed with dilute acid,12 and the... 

In qualitative analysis copper is detected by precipitation as cupric sulphide from hydrochloric-acid solutions of its salts. To prevent the formation of a colloidal precipitate, the solution should be hot, and should contain excess of the acid. The sulphide is soluble in hot, dilute nitric acid, and in potassium-cyanide solution, but almost insoluble in solutions of alkali-metal sulphides. It dissolves to some extent in ammonium-sulphide solution. Other aids in the detection of copper are the blue colour of solutions of cupric-ammonia salts the reddish-brown precipitate of cupric ferrocyanide, produced by addition of potassium ferro-cyanide to cupric solutions the formation of an intense purple coloration by the interaction of hydrogen bromide and cupric salts, a very delicate reaction2 the formation of a bluish-green borax bead and the ready isolation of the metal from its compounds by the action of reducers. 

Triethylarsine dibromide, (C3H5)3AsBrj.— Triethylarsine sulphide is treated with concentrated hydrobromic acid, or triethylarsine with bromine in alcoholic solution. It crystalli.ses from chloroform in deliquescent needles, easily soluble in water and alcohol, insoluble in ether. Chlorine or nitric acid eliminates the bromine, and with concentrated sulphuric acid decomposition takes place with evolution of hydrogen bromide. 

A pyridothiazine may be synthesized efficiently by stirring a 2-mercapto-3-aminopyridine in an alkaline medium. When an organic sulphide such as (11.5) is heat with ethanolic hydrogen bromide under argon, cyclization occurs in good yield. 

Hydrogen chloride HQ 368027 355628 Hydrogen bromide HBr 421029 412828 Hydrogen iodide HI 472430 448828 Hydrogen cyanide 602731 Hydrogen sulphide H2S 4680 446342 467928 Ammonia NH3 -558143 6000( )17 5S7344 579745... 

The main purpose of this article is to present a survey of the results, which have been obtained in our laboratories and by other researchers, on the pyrolysis of light alkcuies from to C5, around 500 C, in the presence of three hydrogenated additives hydrogen chloride, HCl, hydrogen bromide, HBr, hydrogen sulphide, H S the thermal decompositions have been performed at relatively small extents of reaction. 

Dithiins and Related Compounds.—Diacetylenic sulphides react with Na2X (X = S, Se, or Te) to give the mono- and di-substituted heterocycles (24). Other syntheses of 1,4-dithiins from acetylenes are the reactions of amidines of phenylpropiolic acid with sulphur (or selenium) in DMF, and of dimethyl acetylenedicarboxylate with hydrogen bromide in liquid sulphur dioxide. In the latter reaction, sulphuric acid is formed by disproportionation. 

Hydrogen cyanide Hydrogen fluoride Hydrogen selenide Hydrogen sulphide Methyl bromide (bromomethane)... 

The classical reaction of hydrogen sulphide with nitriles in basic media is catalysed by the addition of, for example, Aliquat or tetra-n-butylammonium bromide [4], The reaction proceeds most rapidly with dilute aqueous solutions of sodium sulphide under l -2 atmospheres of hydrogen sulphide to produce thioamides in good yields (>70%). 

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