1,2-Bromofluorides

Bromine trifluoride 17, 626 N-Bromoacetamide as reagent 16, 942 17,590 1,2-Bromofluorides (s. a. 5a-Bromo-6y5-fluorosteroids)... 

Bromoethyl)benzene, reaction with ethyl phenylacetate, 47, 72 ic-Bromofluorides from olefins, 46,12 Bromofluorination of olefins, 46, 39... 

Phosphorotrithioite, 21 61 Phosphorus, 33 106-107 acids, pK values of, 3 383 bond angles in trihalides, 13 365 bromochlorides, 7 12 bromofluorides, 7 8-9, 10 chalcogenide halides, 23 400 chloFofluorides, 7 8, 9-10 complexes, xenon fluoride reactions, 46 86 compounds... 

Alkenes are converted into the corresponding bromofluorides by reaction w ith 1,3-di-bromo-5,5-dimethylhydantoin and silicon telrafluoride in aqueous dioxane in a highly regio-and stereoselective manner,54 Both A-ehlorosuecinimide and A/-iodosuccinimide arc ineffective in this halofluorination. 

The method is general for forming wc-bromofluorides, which in turn are useful intermediates this is exemplified in their conversion to 2-fluoroalkanoic acids.2 The procedure can be applied, with minor modification, to many types of alkenes.3... 

Vinylfluorides.1 This combination results in formation of a reagent BrF (1), which reacts with alkenes by trans-addition to form bromofluorides 2. On elimination of HBr (KOH), the adducts form vinyl fluorides stereospecifically. 

Compound V eliminates magnesium bromofluoride and is probably converted to an epoxide, which rearranges to compound W, 2-chloro-2-phenylpropanal. Elimination of magnesium bromofluoride instead of magnesium bromochloride is probably due to stronger affinity of magnesium to fluoride ion [108]. 

The synonyms of carbonyl bromide fluoride include carbonic bromide fluoride (ACS nomenclature), carbonyl bromofluoride, carbon oxybromide fluoride and bromofluorophosgene. The lUPAC name is carbonyl bromide fluoride. The Chemical Abstracts Registry number for COBrF is [753-56-0]. 

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. ... 

Bromofluoro compounds are themselves useful starting materials for the preparation of monofluorinated compounds. For example, reduction of 1-bromo-2-fluorocyclododecanes with tributyltin hydride gives fluorocyclododecane, while other methods to produce this compound have been unsuccessful.15 The elimination of hydrogen bromide from vicinal bromofluorides also gives vinyl fluorides in good yields,10 16 as is illustrated by the recent synthesis of several substituted a-fluorostyrenes for studies related to [4+2]-cycloadditions.17... 

In 1951 Jonas reported the preparation of sulfuryl bromofluoride in the laboratory of O. Ruff in 1937. The substance was produced by the reaction of (a) BrF3 with CC13S02C1, (b) sulfur dioxide with bromine and bromine trifluoride. It is very stable but reacts vigorously with water. The density... 

Isolated by column chromatography. Chromatography was done in a 20-cm glass column of 2-cm diameter with 25 g silica gel (70-260 mesh, Merck) per g of the bromofluoride using about 500 mL of cyclohexane/ethylacetate (9 1). 

COFg Is also conveniently prepared In a completely CF -free form via the reaction of BrFgWithCO. This procedure is described in detail vmder the preparation of carbonyl bromofluoride (p. 210). 

Carbonyl bromofluoride is preferably stored in quartz ampoules kept in liquid nitrogen. It can also be kept at room temperature in quartz containers or type 304 stainless steel cylinders, but it becomes yellow-brown with time and must be redistilled before use. 

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