L-Bromo-2-fluoroethane

In Chapter vi the introduction of the 2-fluoroethyl group by the action of l-bromo-2-fluoroethane on triethyl phosphite,3 giving diethyl 2-fluoroethylphosphonate (XI), is considered ... 

Fluoroethyl)-5,6-dihydro-4/f-l,3,4-oxadiazines are accessible by ring closure of acylhy-drazides with l-bromo-2-fluoroethane (6.17.7.2.2.1) and fully saturated 1,3,4-oxadiazines arise by condensation of ()8-hydroxyethyl)hydrazines with aldehydes (6.17.7.2.3.1). 

An attempt to prepare l bromo-2-fluoroethane by the partial fluorination of ethylene dibromide by means of antimony trifluoride was not very successful. The compound was best prepared by the action of phosphorus tribromide on F.E.A. The compound was relatively non-toxic and the bromine atom rather unreactive, but considerably more reactive than the chlorine atom in chlorofluoroethane. For example, bromofluoroethane was readily converted by means of potassium thiocyanate into 2 Jivoroethyl thiocyanate. As a lethal inhalant the toxicity of the thiocyanate was inferior to that of M.F.A. Toxicity by injection, however, appeared to be higher. 

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