Br[CH2:2][CH2:3][C:4]1[CH:9]=[CH:8][C:7]([Br:10])=[C:6]([Br:11])[C:5]=1Br.[OH-].[Na+].[Br:15]C(C1C=CC=CC=1)=C(Br)Br>[Br-].C([N+](CC)(CC)CCCC)C.N([O-])=O.[Na+].C(O)(C)C>[Br:15][C:9]1[CH:8]=[C:7]([Br:10])[C:6]([Br:11])=[CH:5][C:4]=1[CH:3]=[CH2:2]105.5 g β-bromoethyl tribromobenzene (as above) (0.25 mol), 1 g triethylbutyl ammonium bromide (as 50% aq.solution) 50 g isopropyl alcohol and 1 g sodium nitrite were stirred at about 500 rpm. in a 1 liter three-necked flask at room temperature. 55.6 g 45% NaOH solution (0.625 mol) were added slowly such that the reaction exotherm gradually raised the temperature to 35° C. When necessary an ice-water bath was raised under the flask to control the temperature. After about 5 minutes of reaction, tribromostyrene started to precipitate from the solution. The stirring was continued for a total of 45 mins. At the end of this period the reaction mixture was filtered using a water vacuum pump. The solid remaining in the funnel was tribromostyrene. The filtered liquid consisted of three separate phases--an aqueous mixture of sodium bromide and hydroxide, an isopropanol phase and a small dark layer containing the heavies. The tribromostyrene was dissolved in n-hexane (approx 150 g), washed with dilute HCl and water and dried over calcium chloride. After filtering off the calcium chloride, the hexane was removed under vacuum at 40° C. until the first crystals appeared. The hexane solution was allowed to cool slowly to room temperature and then in an ice-water bath. The crystals were filtered off, and dried overnight in a vacuum oven at 40° C. 62 g 2,4,5-tribromostyrene were obtained (m.p=64° C.). In the mother liquor (hexane) were dissolved approx. 12 g of products consisting of a mixture of tribromo and tetrabromostyrenes. The isopropanol phase contained about 8 g of product mixtures including dibromostyrene.
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