Font Size: a A A

Chloromethyl Aromatics And The Oxidation Reaction Of Benzyl Chloride

Posted on:2010-05-22Degree:MasterType:Thesis
Country:ChinaCandidate:W WeiFull Text:PDF
GTID:2191360275498786Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
Surfactant and phase transfer catalyst are two types of environment-friendly catalysts. Their aqueous solutions can be directly used as reaction solvents.Compared with the tranditional organic solvents,they have many advantages.Chloromethylation of aromatic hydrocarbons and oxidation of benzyl halides are two types of important reactions and have comprehensive application in organic synthesis.In this paper,surfactant and phase transfer catalyst were respectively used in the chloromethylation and the oxidation.(1) Chloromethylation:Micellar catalysis was employed for chloromethylation. Isopropyl benzene(IPB)was used as model subatrate.The effects of different factors such as the types of surfactants,micelle concentration,reaction temperature,reaction time,and chloromethylation reagents were investigated to improve the yield and the selectivity.Then these conditions were applied to chloromethylation reaction of aromatic hydrocarbons.The mechanism of micellar catalysis for chloromethylation of IPB was also studied.The results show that:Micellar catalysis is a good way for the chloromethylation and cationic surfactants, especially those containing longer hydrophobic carbon chains i.e.CTAB,are more effective. The optimum conditions were as follow:n(IPB):n((HCHO)n):n(NaCl)= 1:1.2:2,CTAB (14CMC),reaction temperature 80℃,reaction time 4h.Under this conditions,98.0% conversion of IPB was obtained.Selectivity reached to 97.5%,the ratio of para/ortho was 10.1:1.This method can be applied to a large amount of actived aromatic hydrocarbons.(2) Oxidation:The oxidation of benzyl chloride with potassium nitrate catalyzed by phase transfer catalysts in both H2SO4 and cation exchange resin systems were investigated. In order to improve the yield and selectivity,different factors were examed to search for the best reaction conditions.The optimum reaction conditions were as follow:n(benzyl chloride): n(KNO3):n(cation exchange resin(?):001×7):n(PEG-600)= 1:1.1:1.5:0.05,H2O 120mL/mol, reaction time 6h under N2 atmosphere.Under this conditions,the conversion of benzyl chloride was 95.4%and selectivity in benzaldehyde was 99.0%.This oxidation procedure can be also applied to a large range ofbenzyl chlorides.
Keywords/Search Tags:Aromatic hydrocarbon, Chloromethylation, Micellar catalysis, Oxidation, Potassium nitrate, Phase transfer catalysis, Cation exchange resin, Benzyl chloride
PDF Full Text Request
Related items