Vinylbenzyl iodide

Vinvlbenzvl Iodide—Vinylbenzyl chloride (20 g 0.131 mol) was added dropwise to dry sodium iodide (29.5 g 0.198 mol) in 130 mL dry acetone. The mixture was stirred at 50°C for 40 min, cooled to room temperature, and filtered. The acetone was removed by rotary evaporation, and 100 mL water and 150 mL ether were added to the solid residue. The aqueous layer was washed with ether. The combined ether layers were washed with water containing 2% sodium thiosulfate and dried over magnesium sulfate. The ether was removed by rotary evaporation and the yellow residue was dissolved in 50 mL hexane and cooled to -20°C. Within 1.5 hr, yellow crystals formed. Fast filtering with chilled glassware provided 17.1 g (53.5% of theory) of vinylbenzyl iodide. 

Sharkey20 found that living poly(methyl methacrylate) reacts efficiently and without side reaction with p-vinylbenzyl iodide (or bromide) at low temperature yielding poly(methyl methacrylate) macromonomers bearing at the chain end a styryl group (poly(methyl methacrylate)macromonomer). 

Styrene-type macromonomers were also prepared by reaction of living PtBuA and PMMA chains with p-vinylbenzyl chloride, iodide or bromide , 4-(chlorodimethyl-silyl)styrene and 4-(chlorodimethylsilyl)-a-methylstyrene , respectively. 

Poly(vinylbenzyl mercaptan) has been described by several authors. The synthesis always follows the same path chloromethylation of polystyrene followed by reaction with thiourea and hydrolysis of the isothiuronium salt 1,53,55,63-65). The redox properties of a polymer obtained from chloromethylated styrene-divinylbenzene copolymers have been evaluated (3). Redox capacities givrai for mercaptyl resins were determined to be 2. W>-5.27 milliequivalents of iodine reduced per gram of (dry) resin in aqueous potassium iodide. The oxidized form of the resin could be easily reduced with 10% aqueous bisulfite fmr a complete redox cycle. Recently polyvinylbenzyl mercaptan resins were prepared directly by treating chloromethylat polystyrene with KSH in dimethyl formamide (66). 

---