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聚乙二醇用作改善亲核取代反应的相转移催化剂
Polyethylene Glycol(PEG) as Phase Transfer Catalyst for Improvement of Nucleophilic Substitution on Ring A of Bromoestrogen to Methoxyestrogen
【摘要】 研究了将聚乙二醇用作相转移催化剂及其对亲核取代反应的改善.先将雌二醇经溴化制得2或4溴雌二醇,再分别在氯仿中以聚乙二醇(PEG400)作相转移催化剂(PTC)进行亲核取代反应制备2或4甲氧基雌二醇.发现其适宜条件为:反应温度60~65℃,搅拌反应时间1.5h,试剂比例底物为甲醇KOHPEG=120800.8,获得较高亲核取代产率:2甲氧基雌二醇66.7%及4甲氧基雌二醇70.3%,结果良好,操作简便.
【Abstract】 Polyethylene Glycol(PEG)is studied to be used as phase transfer catalyst (PTC) for organic synthesis. In this paper,nucleophilic substitution of 2 or 4 bromoestrogen,prepared from estradiol,by bromination with N bromosuccinimide(NBS),to 2 or 4 methoxyestogen by methoxidion with methanot,,was catalysed by the PTC,PEG 400 .The proper experimental conditions are found to be:chloroform as solvent,reaction temperature being 60~65 ℃, stirring reaction time being 1.5 h,regent ratio being bromoestrogenMeOHKOHPEG=120800.8. The yields of nucleophilic substitution reaction are 66.7% and 70.3% for 2 and 4 methoxyestrogens,respectively.
【Key words】 ployethylene glycol(PEG); phase transfer catalyst(PTC); nucleophilic substitution; bromoestrogens; methoxyestrogen estrogen;
- 【文献出处】 湖南大学学报(自然科学版) ,JOURNAL OF HUNAN UNIVERSITY(NATURNAL SCIENCES) , 编辑部邮箱 ,1997年04期
- 【分类号】TG174.42
- 【被引频次】4
- 【下载频次】304