preparation and application of 3-bromostyrene_kain industrial additive

background and overview^[1][2]

3-bromostyrene, also called 1-bromo-3-vinylbenzene, is a pharmaceutical intermediate that can be prepared in one step from m-bromobenzyl bromide and paraformaldehyde.

preparation^[1-2]

report 1,

add 163.2mg k₂co₃ (the molar ratio to m-bromobenzyl bromide is 1.5) into a schlenk test tube equipped with a magnetic stirrer. :1), 314.4mg triphenylphosphine (molar ratio to m-bromobenzyl bromide is 1.5:1), 3.8mg ru(bpy)3cl2-6h2o (molar ratio to m-bromobenzyl bromide is 0.005:1), 60mg paraformaldehyde, 10ml acetonitrile, 248mg 3-bromobenzyl bromide, argon gas for 5 minutes, under visible light, room temperature, reaction time is 4h, the product is separated and purified through petroleum ether, and the product is 162mg 3-bromostyrene. the yield is 89%.

3-bromostyrene: ¹h nmr (cdcl₃, 400mhz) δ7.56 (s, 1h), 7.53 (d, j = 8.24hz, 2h), 7.39 (d, j＝7.79hz, 1h), 7.32 (d, j＝7.79hz, 1h), 7.20 (t, j＝7.79hz, 1h), 6.65 (dd, j1＝ 17.63hz, j2＝ 10.99hz,1h),5.76(d,j＝17.40hz,1h),5.30(d,j＝10.99hz,1h).¹³c nmr (cdcl₃ , 100mhz)δ139.8,135.6,130.8,130.2,129.3,125.0,122.9,115.5.ei-ms:m⁺m/z 182.

report 2,

dissolve 3-bromobenzaldehyde (10g, 54.05mmol) in 102ml dioxane and water (v/v=50:1) mixed solvent, add potassium carbonate (18.64g, 135mmol) and methyl trisulfide phenylphosphonium iodide (43.70g, 108.11mmol) was heated to 100°c and stirred for 12 hours. filtration, the filter cake was washed with 200 ml n-hexane and ethyl acetate (v/v=50:1) mixed solvent, the filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography to obtain the title product 3-bromostyrene (10g , yellow liquid), yield: 100.0%.

apply^[3]

cn201810108131 reports a flame-retardant polystyrene foamed wood-like material and a preparation method thereof. the material is made of the following raw materials in terms of mass percentage: flame-retardant copolymer polystyrene 30- 50%, small molecular weight polytetrafluoroethylene 20-45%, inorganic flame retardant filler 10-25%, foaming agent 1-3%; among them, flame retardant copolymer polystyrene is composed of vinyl diethyl phosphate, it is produced by copolymerizing 4-bromo-β,β-difluorostyrene, tribromoethylene, 3-bromostyrene and triphenylvinylsilane as raw material monomers. the polystyrene foam material provided by the invention has good mechanical properties and long-lasting flame retardant properties.

main reference materials

[1] [chinese invention] cn201710201407.4 a method of light-induced one-pot synthesis of olefin compounds

[2] [china invention, china invention authorization] cn201210300982.7 benzodioxane derivatives, their preparation methods and their applications in medicine

[3] cn201810108131.x a kind of flame-retardant polystyrene foamed wood-like material and its preparation method