Tris - -bromide

Both reactants m the Williamson ether synthesis usually originate m alcohol pre cursors Sodium and potassium alkoxides are prepared by reaction of an alcohol with the appropriate metal and alkyl halides are most commonly made from alcohols by reaction with a hydrogen halide (Section 4 7) thionyl chloride (Section 4 13) or phosphorus tri bromide (Section 4 13) Alternatively alkyl p toluenesulfonates may be used m place of alkyl halides alkyl p toluenesulfonates are also prepared from alcohols as their imme diate precursors (Section 8 14)... 

ARSENIC TRI BROMIDE ARSENIC TRICHLORIDE ARSENIC TRIFLUORIDE ARSENIC PENTAFLUORIDE ARSINE... 

Halides and Oxyhalides. Thermodynamic data have been presented for MF compounds (M = Nb or Ta, n = 1—5). ° The equilibrium pressure of dissociation of NbBr4 into the penta- and tri-bromides, as... 

Nitrogen tri bromide, trichloride and triiodide these are all highly sensitive and violently explosive, and should never be prepared or used unless absolutely necessary. 

The procedure 1n the present reaction sequence for the preparation of N-bromomethylphthalimide (2) is a modification of that reported by Pucher and Johnson. N-Bromomethylphthallmide has also been prepared by treatment of 11-hydroxymethyl phthali mi de with phosphorus tri bromide. The procedures for the syntheses of the phosphonates 3 and 4 represent modifications of those described by Yatnauchi and co-workers. Two other routes to 4 have recently been reported by Gross and co-workers. Ratcliffe and Christensen have also recorded the preparation of diethyl N-benzylldeneaminomethylphosphonate (5) by the condensation of benzaldehyde with 4 under virtually identical conditions as detailed herein, but their route to 4 was completely different. The submitters have found that the present method for the syntheses of 2-5 gives reproducibly higher yields and is more reliable and convenient than those alternative procedures. 

The ionically bonded sodium bromide receives two electrons, and loses two +ve sodium cations to form sodium tri-bromide (see Porterfield, 1993). An alternative homogeneous reaction route to tri-bromide is to bubble bromine (Br2) through aqueous sodium bromide. Accordingly, the electrochemically formed tri-bromide has an associated atmosphere of bromine from homogeneous dissociation. Such bromine is corrosive, but is contained by the fluorinated plastic tanks and by one side of the (Na ) Nafion perm-selective membrane. Nafion is itself a compound with many fluorine atoms. Bromine is very much lower than fluorine in chemical reactivity, so that the bromine containment strategy is complete, and the selection of the bromide electrolyte seen to be a well-considered choice. 

Acetylaminophenylarsine (2-1 parts) is dissolved in 30 parts of methyl alcohol containing hydrogen bromide, and 4 5 parts of bismuth tri-bromide in methyl alcohol added. Addition of ether precipitates a heavy, black powder, decomposed by acids and alkalis. 

Acyl Radical.—The names of the acid chlorides are derived from the names of the acids by changing the termination ic to yl. Thus, CHa—CO—Cl is acetyl chloride or ethanoyl chloride. The acid chlorides of the lower acids are liquids which possess a very penetrating and disagreeable odor and boil at a lower temperature than the corresponding acid. Analogous compounds of bromine and iodine are formed by the action of phosphorus tri-bromide or phosphorus triiodide on the acids. These are ... 

Phenylseleno phenyl tellurium reacted with bromine to form phenyl tellurium tribromide and phenyl selenium tri bromide ... 

As indicated by Equation 1, a standard procedure for ozone recommends the addition of iodide ions and the titration of the liberated iodine. There is a serious problem in interpreting the results of the iodide reaction The quantity of iodine liberated is pH dependent. Inglis (6) reported that acid solutions gave more than one molecule of iodine per molecule of ozone. He tried bromide in normal nitric acid but obtained decreasing amounts of bromine from aliquots of the original ozone solution with time, while the iodine liberated from iodide remained constant. He concluded that the bromide-bromine reaction was unsatisfactory. Alder and Hill (1) found that ozone decomposes, according to its ultraviolet spectrum, faster than the decreasing ability of the same solution to liberate iodine from iodide. They concluded that a decomposition product of ozone, the hydroperoxyl ion, liberates iodine from iodide in the absence of ozone. 

PBr3 PHOSPHORUS TRI BROMIDE 56.758 1.0427E-01 -1.6430E-04 1.1542E-07 -2.9670E-11 298 1500 gas... 

Trachelanthamidine (XXXVib) has been synthesized by Kotchetkov and his collaborators (131, 132) by ring closure of the tri-bromide, XXXIX, with ammonia and reduction with lithium aluminum hydride. 

Phosphorus Oxybromide. Phosphoryl bromide phosphoryl tri bromide- Rr3OP mot wt 286.72. Br 83.62%. O 5.58%, P 10.80%. POBr-. Prepd according to the equation 3PBrs + PjOj — 5POBr3 Hrintgschmid, Hirschbold-... 

Preparation.—This substance cannot be obtained fromabromid as HCl is obtained from a chlorid. It is produced, along with phosphorous acid, by the action of HjO upon phosphorus tri-bromid PBr,-j-3HjO = HsPOa-1-3HBr or by the action of Br upon paraffin. 

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