Compounding with bromine

Naphthalic anhydride has been prepared by the hydrolysis of the dinitrile of ,2-naphthaIic acid,1 by the oxidation of suitably substituted hydrocarbons or ketones,2 or by the dehydrogenation of the 3,4-dihydro compound with bromine 3 or with sulfur.4... 

Compounds with Bromine and Iodine. The available thermody-namic data on these compounds are listed in Table III. 

It has already been known that the reaction of primary amines with alkaline hypobromite gives nitriles, and the reaction of hydrazo compounds with bromine affords azo compounds. Recently, we also found that the reaction of primary amines and hydrazo compounds with BTMA Br3 in aq. sodium hydroxide or in water gave corresponding nitriles and azo compounds in satisfactory yields, respectively (Fig. 27) (ref. 35). 

Dehydrogenation of hydrazo compounds with bromine, 32, 16 Dehydrohalogenation by sodium amide, 30, 72... 

The stereochemistry of the product of a reaction will be influenced by the structures of the reagent and substrate and the mechanisms by which they react. For example, the hydroxylation of but-2-ene by osmium tetroxide and water yields a racemate whilst bromination of the same compound with bromine produces a meso compound (Figure 10.5). Flowever, a stereoselective reaction is most likely to occur when steric hindrance at the reaction centre restricts the approach of the reagent to one direction (Figure 10.6). Furthermore, the action of both enzyme and non-enzyme catalysts may also be used to introduce specific stereochemical centres into a molecule. 

The dehydrochlorination of 4-(l-chloroalkyl)azetidin-2-ones with dimethyl sulfoxide offers a new route to 3,4-zfr-4-isopropenylazetidin-2-ones 369 (Equation 138) <2005JOC8717>. The reaction of the latter compounds with bromine (Scheme 53) or with a mixture of iV-bromosuccinimide and trimethylsilylazide (Equation 139) led to an electrophile-induced ring expansion toward pyrrolidin-2-ones 370 and 371. 

Other organic reactions take place between completely uncharged molecules with no dipole moments. One of the old tests for unsaturation was to treat the compound with bromine water. If the brown colour disappeared, the molecule was unsaturated. We don t use tests like these any more (spectroscopy means we don t need to) but the reaction is still an important one. A simple symmetrical alkene combines with symmetrical bromine in a simple addition reaction. 

Carbosilanes with Si- and C-functional groups that can be used for cyclization are obtained by the reaction of phenyl compounds with bromine ... 

The compound does not glow in air, but is highly inflammable, giving a mixture of the oxides. It was attacked only slowly by cold water, but rapidly by hot water, giving phosphoric acid and hydrogen sulphide.11 It did not form addition compounds with bromine or iodine.12 It was converted into PSC13 by phosphorus pentachloride and by several other acid chlorides —13... 

An element s most stable ion forms an ionic compound with bromine, having the formula XBr2. If the ion of element X has a mass number of 230 and 86 electrons, what is the identity of the element, and how many neutrons does it have ... 

Bromination (Sections 10.13, 15.6, 18.3) The reaction of a compound with bromine. 

As in the case of chlorine, there exist five binary compounds from WBr to WBr2, and two ternary compounds with bromine and oxygen, WOBr4 and W02Br2. 

On p. 479 of the textbook we explain the formation of 2,4,6-tribromophenol by bromination of phenol in water. It looks as though we can go no further as all the ortho and para positions are brominated. But we can if we treat the tribromo-compound with bromine in an organic solvent. Account for the formation of the tetrabromo-compound. 

Reaction of the arylthallium(III) compound with an electrophile affords an intermediate cationic arylthallium derivative (90), which then undergoes elimination of the thallium moiety. Examples of this type of reactivity are the reactions of arylthallium(III) compounds with bromine affording aryl bromide, with iodine affording aryl iodide, 1 8-110 or with nitrosyl chloride giving nitroso-benzene. l ... 

Pyrido[3,4-d]pyridazine shows unexpected reactivity towards bromine, as treatment of the compound with bromine in methanol at 20 °C followed by potassium carbonate gives 8-bro-mopyrido[3,4-d]pyridazine (6) in 75% yield.6 129... 

Characterized as the alkyl bromide after treatment of the alkylzirconium compound with bromine. 

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