Enantioselective synthesis of (+) and (–)-2-[1-(2,6-dichlorophenoxy)-ethyl]-1,3-diazacyclopent-2-ene
申请人:University of Kentucky Research Foundation
公开号:US08101779B2
公开(公告)日:2012-01-24
Methods for the enantioselective synthesis of (+) and (−) lofexidine or 2-[1-(2,6)-dichlorophenoxy)-ethyl]-1,3-diazacyclopent-2-ene involve converting (+) or (−) 1-methyl-1-[2,6-dichlorophenoxy]ethanamide to an (+) or (−) imino-ether intermediate by electrophilic attack of the amide oxygen by a trimethoxonium ion and, without isolation, converting the (+) or (−) imino-ether intermediate to (+) or (−) 2-[1-(2,6-dichlorophenoxy)-ethyl]1,3-diazacyclopent-2-ene by adding ethylene diamine; and optionally converting the (+) or (−) 2-[1-(2,6-dichlorophenoxy)-ethyl]1,3-diazacyclopent-2-ene into a pharmaceutically acceptable acid addition salt thereof.
(+)-和(−)-洛非辛或2-[1-(2,6-二氯苯氧基)乙基]-1,3-二氮杂环戊-2-烯的对映选择性合成方法包括通过三甲氧基离子的亲电攻击使(+)-或(−)-1-甲基-1-[2,6-二氯苯氧基]乙酰胺转化为(+)-或(−)-亚胺醚中间体,然后在不隔离的情况下通过添加乙二胺将(+)-或(−)-亚胺醚中间体转化为(+)-或(−)-2-[1-(2,6-二氯苯氧基)乙基]-1,3-二氮杂环戊-2-烯;并且可以将(+)-或(−)-2-[1-(2,6-二氯苯氧基)乙基]-1,3-二氮杂环戊-2-烯转化为其药学上可接受的酸盐。