Mercuric oxide, reaction with bromine

Mercuric acetate, reaction with cyclo-octatetraene, 50, 24 Mercuric oxide, use in oxidation of hydrazones, 50, 28 with 3-chlorocyclobutanecarboxylic acid and bromine to give 1-bromo-... 

The following reactions with inorganic substances are taken from the book of Clark, Hydrazine (1953), pp 4 to 18 Potassium reacts with N2H4 expl violently (p 4) Mercuric oxide reacts with N2H4.H2O with expl violence (p 5) Chlorine, bromine and iodine react violently (p 8) with N 2H4 and spontaneous ignition of N2H) takes place in a chlorine atm. 

Tetrahydrobenzo[ ]thiophene behaves like thiophene in electrophilic substitution reactions. Thus, it is formylated with a mixture of vV-methylformanilide and phosphorus oxychloride,436 iodinated in the presence of mercuric oxide,193 and brominated by V-bromosuccinimide,193 all in the 2-position in Friedel-Crafts reactions with acetyl chloride,194-436 propionyl chloride,436 succinic... 

Elaboration of the thiophene ring can be achieved by standard electrophilic substitution reactions, which are normally favored at the a-carbons for thiophene and at the 3-position for benzo[fc]thiophene. Reductive alkylation of aminocarbamate 72 with butyraldehyde in the presence of selenophenol gave thiophene 73 . Treatment of 3-methylthiophene with chlorosulfonic acid followed by tcrt-butylamine led to selective sulfonamidation producing 74 . Similarly, selective 2-iodination of 3-alkylthiophenes was ob.served upon treatment with iodine in the presence of mercuric oxide . Exhaustive bromination of thieno[3,2-7i]thiophene 27 gave 2,3,5,6-tetrabromothieno[3,2-ii]thiophene which was... 

The aHphatic iodine derivatives are usually prepared by reaction of an alcohol with hydroiodic acid or phosphoms trHodide by reaction of iodine, an alcohol, and red phosphoms addition of iodine monochloride, monobromide, or iodine to an olefin replacement reaction by heating the chlorine or bromine compound with an alkaH iodide ia a suitable solvent and the reaction of triphenyl phosphite with methyl iodide and an alcohol. The aromatic iodine derivatives are prepared by reacting iodine and the aromatic system with oxidising agents such as nitric acid, filming sulfuric acid, or mercuric oxide. 

In a modified procedure the free carboxylic acid is treated with a mixture of mercuric oxide and bromine in carbon tetrachloride the otherwise necessary purification of the silver salt is thereby avoided. This procedure has been used in the first synthesis of [1.1.1 ]propellane 10. Bicyclo[l.l.l]pentane-l,3-dicarboxylic acid 8 has been converted to the dibromide 9 by the modified Hunsdiecker reaction. Treatment of 9 with t-butyllithium then resulted in a debromination and formation of the central carbon-carbon bond thus generating the propellane 10." ... 

The rate-determining step was, therefore considered to be reaction of bromine with peroxyacetic acid to give a species (suggested as bromine acetate)which subsequently and rapidly, brominates. Formation of bromine acetate was believed to take place according to the reaction scheme represented by equilibrium (158) (which is analogous to the mercuric oxide oxidation of bromine) followed by either equilibrium (159), (160) or (161), viz. 

A related method for conversion of carboxylic acids to bromides with decarboxylation is the Hunsdiecker reaction.276 The usual method for carrying out this transformation involves heating the carboxylic acid with mercuric oxide and bromine. 

Reaction of the parent heterocycle with excess of bromine affords 2,3,4,5-tetra-bromoselenophene in quantitative yield (36BCJ157). 2-Iodoselenophene and its homologues have been obtained by iodination with iodine in the presence of mercuric oxide (56JGU3517) or by the iodine-iodic acid method (75CS(7)lll). 

Although some bromine oxides have been studied, all appear to be unstable at temperatures above -40 °C. The monoxide is prepared by the reaction of bromine with mercuric oxide,... 

Hunsdiecker reaction. In the original Hunsdiecker reaction, the silver salt of an acid is prepared in one step and treated with bromine in another. Cristol found that isolation of a metal salt can be dispensed with addition of bromine to a refluxing snspension of red mercuric oxide in a solution of the acid in carbon tetrachloride affords the corresponding alkyl halide in good yield ... 

Oxidative decarboxylation of optically active l-methyl-2,2-diphenylcyclopropanecarboxylic acid (10) with lead tetraacetate in the presence of iodine leads to racemized 1-iodo-l-methy 1-2,2-diphenylcyclopropane (11) in 45% yield. Subjecting 10 to the Cristol-Firth modification of the Hunsdiecker reaction (bromine and mercuric oxide in carbon tetrachloride) leads to racemic 1-bromo-l-methyl-2,2-diphenylcyclopropane (12) however, the yield is poor (5 /o). ... 

Dibromocyclopropane is obtained in 36% yield from the reaction of cyclopropane-1,1-dicarboxylic acid with bromine and mercuric oxide in refluxing dichloromethane. ... 

ZINC CYANIDE (557-21-1) Zn(CN)j Noncombustible solid. May tend to be an unstable explosive. Reacts with acids, acid fumes, acid salts, or elevated temperatures releases flammable and poisonous hydrogen cyanide gas. Can react violently with magnesium (incandescence), chlorates, nitrates, perchlorates. Incompatible with nitrites, chlorates. Mixtures of metal cyanides with metal chlorates, nitrates, nitrites, or perchlorates may cause violent explosions. Incompatible with strong oxidizers, bromine, chlorine, fluorine, mercurous chloride, nitric acid. Violent reaction with sodium nitrite. Forms sensitive explosive mixtures with potassium chlorate. ZINC DIACETATE (557-34-6 5970-45-6, dihydrate) Zn(C2H302)2 Noncombustible... 

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