{"title":"Selective chlorination of side-chains in Friedel-Crafts polymers","authors":"P. J. Blincow, J. S. Ghotra, G. Pritchard","doi":"10.1002/PI.4980180610","DOIUrl":null,"url":null,"abstract":"Aralkyl polymers with ethyl side-chains were prepared by Friedel-Crafts reactions. Ethylbenzene and bis(p-chloromethyl)benzene (BCMB) were reacted together in the presence of stannic chloride to produce polymers of various molecular weights. A study was then carried out of the chlorination of these polymers, using (a) molecular chlorine, (b) molecular chlorine with a peroxide catalyst and phosphorus pentachloride, (c) sulphuryl chloride. The objective was to determine the best conditions for chlorination to occur selectively at the α-carbon atom of the ethyl group, with minimal chlorination at either the β-position or the main-chain methylene groups. Analysis of 1H nuclear magnetic resonance spectra of the chlorinated polymers suggests that in most cases chlorination occurs extensively both in the side-chain and in the main-chain methylene groups. Conditions were found, however, which favour chlorination at the α-position. The greatest selectivity was achieved when molecular chlorine, a peroxide catalyst and phosphorus pentachloride were used in benzene solvent.","PeriodicalId":9298,"journal":{"name":"British Polymer Journal","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1986-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"British Polymer Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1002/PI.4980180610","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Aralkyl polymers with ethyl side-chains were prepared by Friedel-Crafts reactions. Ethylbenzene and bis(p-chloromethyl)benzene (BCMB) were reacted together in the presence of stannic chloride to produce polymers of various molecular weights. A study was then carried out of the chlorination of these polymers, using (a) molecular chlorine, (b) molecular chlorine with a peroxide catalyst and phosphorus pentachloride, (c) sulphuryl chloride. The objective was to determine the best conditions for chlorination to occur selectively at the α-carbon atom of the ethyl group, with minimal chlorination at either the β-position or the main-chain methylene groups. Analysis of 1H nuclear magnetic resonance spectra of the chlorinated polymers suggests that in most cases chlorination occurs extensively both in the side-chain and in the main-chain methylene groups. Conditions were found, however, which favour chlorination at the α-position. The greatest selectivity was achieved when molecular chlorine, a peroxide catalyst and phosphorus pentachloride were used in benzene solvent.