Or tribromid

Boron exists naturally as 19.78% lOB isotope and 80.22% IIB isotope. High-purity crystalline boron may be prepared by the vapor phase reduction of boron trichloride or tribromide with hydrogen on electrically heated filaments. The impure or amorphous, boron, a brownish-black powder, can be obtained by heating the trioxide with magnesium powder. 

The interaction of triarylstibines and antimony trichloride or tribromide is a convenient and efficient method for preparing aryldihalo- and diaryUialostibines (104,107,108) ... 

Halobismuthines, Dihalobismuthines, and Related Compounds. Chloro-, dichloro-, bromo-, and dibromobismuthines are best prepared by the reaction of a tertiary bismuthine and bismuth trichloride or tribromide (7,43,45,46,104—107) ... 

Jsomerides of Morphine and Codeine. When morphine is treated with thionyl chloride, phosphorus trichloride or tribromide, the alcoholic hydroxyl group is replaced by the halogen, forming a-chloromorphide and bromomorphide respectively. The former on treatment with concentrated hydrochloric acid is converted into /3-chloromorphide. Schopf and Hirsch have provided evidence that the two are structural isomerides. With the same reagents codeine yields a parallel set of compounds, viz., a- and -chlorocodides, and bromocodide. The chief characteristics of these products may be summarised thus —... 

The stereochemical behavior observed in the addition of BrCl has been compared with that related to the Br2 and CI2 additions to the same diene and discussed in terms of steric hindrance of the nucleophile approach (chloride ion with respect to bromide or tribromide ion) and different bridging in the bromonium or chloronium intermediates77. 

A more efficient method for converting the oxide (258) to 2-azaquinolizinium bromide is by refluxing it in phosphorus tribromide (Scheme 129) <67JCS(C)2391>. Deoxygenation by use of phosphorus trichloride or tribromide proved effective (7lJCS(C)86l) with a number of 2-azaquinolizinium 2-oxides substituted in positions 1 and 3, although the 1-methyl oxide offered some resistance. 

Anhydrous vanadium trichloride or tribromide reacts with acetonitrile to yield green or red-brown solutions. Complexes [VX3(MeCN)3] (X = Cl or Br) crystallize with varying amounts of acetonitrile in the lattice,212 where the IR spectra show the free (2253.5 cm-1) and coordinated (2292 cm-1) acetonitrile. 

Vanadium trichloride or tribromide reacts with thioethers giving [VX3L2] (X = C1 or Br L = SMe2, tetrahydrothiophene or SEt2).288,289 The complex with di-n-propyl sulfide could not be isolated.288 These compounds are oxidized very easily. Solubility, molecular weights and conductance show that they are monomeric and non-ionic. Dipole moments, IR and electronic spectra are consistent with trans trigonal bipyramidal structures. 

In general, hydroxy groups on fused benzene rings undergo the expected reactions. O-Methylation is effected by diazomethane, methyl iodide or dimethyl sulfate. O-Alkylation is reversed by aluminum trichloride or tribromide in benzene or nitrobenzene. 

The phosphorus nitride of the early workers—H. Rose,11 and F. Wohler and J. von Liebig—was probably phosphorus imidonitride, PN2H, or N j P NH, sometimes called phospham. It was made by F. Wohler and J. von Liebig, C. Gerhardt, and H. Davy by heating phosphorus pentachloride in ammonia and by H. Rose, by the action of ammonia on phosphorus pentachloride, trichloride, or tribromide ... 

Bis(trimethylsilyl)ylide 65a reacts with phosphorus trichloride or tribromide to give dihalophosphino(trimethylsilyl)ylide 65b. In a two-step self-condensation, 2 equiv of trimethylsilyl (TMS) halogenide are eliminated and i P-dihalogeno d-diphosphoranediyl-lA3,3A3-diphosphetanes 57 are formed (Scheme 19) <1997CB1519>. 

When aryl tellurium trichlorides or tribromides were treated with aqueous solutions of sodium carbonate or sodium hydroxide4,5 and the resulting solutions acidified with 10% acetic acid, tellurinic acid anhydrides precipitated. 

Onium Aryltetrahalotelliirates(TV) [Aqueous Medium]2 1 mmol of the aryl tellurium trichloride (or tribromide) is dissolved in 6 molar hydrochloric acid (or 3 molar hydrobromic acid) and a solution of 1 mmol of the onium halide in 20 ml of water is added dropwise with stirring. The product precipitates immediately yield 100%... 

Phosphorus Trifluoride, PF3.—Some early indications were obtained that phosphorus reacted with fluorides of zinc and lead,1,2 and that the fluoride resulting was a gas.3 This gas was prepared in 1884 by heating lead fluoride with copper phosphide in a brass tube.4 It is also produced by the action of fluorides of zinc, silver or lead on phosphorus trichloride or tribromide.5 One of the most convenient methods of preparation is by the reaction between arsenic trifluoride, which is easily prepared and purified, and phosphorus trichloride, thus —... 

In the 1 1 adducts of phenyl tellurium trichloride or tribromide with aluminum tribromide or gallium trichloride, the tellurium compound serves as the halide donor. 

Whereas dihydrocodeine can be converted to 6-chlorodihydrocodide [241], dihydroisocodeine gives only phosphorus-containing products on treatment with phosphorus pentachloride or tribromide, whilst thionyl chloride only effects nuclear chlorination, presumably in position 1, the product giving dihydroisocodeine on reduction with sodium and alcohol [240],... 

The harsh conditions of this reaction have limited its general utility for degradative studies, despite its obvious advantages over the Hofmann degradation. It has now been demonstrated that COBtj is a much milder reagent for this reaction, and this has resulted in the isolation of the iminium bromide (or tribromide, [Br3] ) intermediate [662,1612] ... 

Phosphonic and Phosphinic Adds and their Derivatives.—Oxidative chlorophos-phonylation of allyl chloride gives 60% bis(chloromethyl)methylphosphonic dichloride, which may readily be monodehydrochlorinated by triethylamine. Phosphonic bromofluorides and dibromides are both obtained, together with other products, when terminal alkenes react with phosphorus trichloride or tribromide in the presence of FCIO. ... 

The reaction of benzyltriphenylphosphonium bromide (36) with phosphorus trichloride or tribromide and triethylamine leads via the C-dihalophosphino-C-phenyl ylides (37) to the 1,2-dihalo-... 

Condensation of ketene aminals (58 R = H, alkyl, aryl, = CN, C6H4NO2-4) with phosphorus trichloride or tribromide gives 1,3-azaphospholes (59) (Equation (6)) <89EGP268702>. 

Provided moisture is rigidly excluded, phosphorus trichloride or tribromide and a diazoalkane at low temperatures afford a-halo alkyldihalophosphines 342... 

Demethylation normally effected with boron trichloride or tribromide has been realised with the trifluoride in a selective and partial manner. 

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