Ethylene bromide bromohydrin

Problem 14.20 Describe simple chemical tests (if any) that would distinguish between (a) ethylene bromohydrin and ethylene bromide (b) 4-chloro-1-butene and / -butyl chloride (c) bromocyclohexane and bromobenzene (d) 1-chloro-2-methyl-2-propanol and l,2-dichloro-2-methylpropane. Tell exactly what you would do and see. 

The characteristic ease with which ethylene oxides undi ruu nucleophilic attack or isomerization in tbe presence of Lewie acids made them obvious substrates for tbe org nometallic reagents intro duoed by Grignard 07 around the turn of the century, and subsequently named in his hunor. The earliest disclosure of a reaction between an epoxide and a Grignard reagent, however, bears the name of Blaise,1 who noted the formation of ethylene bromohydrin on troii merit of ethylene oxide with raethylmagneeium bromide. In the years... 

The reaction of phenylmagnesium bromide with 1,3,2-dioxathioIane 2-oxide (16) gave 3.4-23% ethylene bromohydrin (131) and 42-60% diphenyl sulfoxide (132), depending on the conditions of the reaction. The bromohydrin (131) arises from a nucleophilic displacement at carbon by bromide ion, presumably via (129) and (130), while the sulfoxide (132) is formed by repeated attack of the Grignard reagent at sulfur (56JA454). 

Substituted alkyl halides undergo, of course, the reactions characteristic of their other functional groups—nitration of benzyl chloride, oxidation of ethylene bromohydrin, addition to allyl bromide —but as halides they react very much like ethyl or isopropyl or /cr/ butyl halides. 

Polytetramethylene glycol of molecular weight 2000 was freeze-dried from benzene in a vacuum. The bromoethylated prepolymer was obtained by reaction of the glycol, first with adipoyl chloride, then with ethylene bromohydrin (Table II) and precipitation in water and n-hexane. Nitromethane solution of the poly-THF dioxolenium salt was prepared after filtration of silver bromide from the reaction product of bromoethylated poly-THF with silver perchlorate in nitromethane. 

One of the earliest nucleophilic reactions of ethylene cyclic sulfite was reported with phenylmagnesium bromide (56JA454). Depending on the reaction conditions, a 3.4 to 23% yield of bromohydrin and a 42-60% yield of diphenyl sulfoxide were isolated [56CI(L)490j. 

---