N-Demethylation of N-methyl alkaloids with ferrocene
作者:Gaik B. Kok、Peter J. Scammells
DOI:10.1016/j.bmcl.2010.06.031
日期:2010.8
ferrocene has been found to be a convenient and efficient catalyst for the N-demethylation of a number of N-methyl alkaloids such as opiates and tropanes. By judicious choice of solvent, good yields have been obtained for dextromethorphan, codeine methyl ether, and thebaine. The current methodology is also successful for the N-demethylation of morphine, oripavine, and tropane alkaloids, producing the corresponding
METHOD FOR THE N-DEMETHYLATION OF N-METHYL HETEROCYCLES
申请人:Scammells Peter John
公开号:US20120226043A1
公开(公告)日:2012-09-06
The present invention provides methods of N-demethylating, N-methylated heterocycles and N-methyl, N-oxide heterocycles using a transition metal with an oxidation state of zero, ferrocene or substituted derivatives thereof, or Cr
3+
. N-demethylated heterocycles prepared by the methods of the present invention are also provided.
Two-Step Iron(0)-Mediated N-Demethylation of <i>N</i>-Methyl Alkaloids
作者:Gaik B. Kok、Cory C. Pye、Robert D. Singer、Peter J. Scammells
DOI:10.1021/jo1008492
日期:2010.7.16
A mild and simple two-step Fe(0)-mediated N-demethylation of a number of tertiary N-methyl alkaloids is described. The tertiary N-methylamine is first oxidized to the corresponding N-oxide, which is isolated as the hydrochloride salt. Subsequent treatment of the N-oxide hydrochloride with iron powder readily provides the N-demethylated amine. Representative substrates include a number of opiate and tropane alkaloids. Key intermediates in the synthesis of semisynthetic 14-hydroxy pharmaceutical opiates such as oxycodone and oxymorphone are also readily N-demethylated using this method.
A METHOD FOR THE N-DEMETHYLATION OF N-METHYL HETEROCYCLES