We disclose the reductive trifluoromethylation of chemically stable homocystine and cystine to provide corresponding trifluoromethyl ethers by the CF3I/Na/Liq.NH3 system. Both non-protected and protected homocystines can be nicely converted into trifluoromethylated methionines under the same condition. The method described offers a robust synthesis of pharmaceutically important trifluoromethionine, suitable for multigram synthesis. Pentafluoroethylation of homocystine was also achieved by the CF3CF2I/Na/Liq.NH3 system. (C) 2011 Elsevier B.V. All rights reserved.
Simple preparation of trifluoromethionine and derivatives thereof
申请人:SHIBATA Norio
公开号:US20110015433A1
公开(公告)日:2011-01-20
Disclosed is a process for the simple preparation of trifluoromethionine, its analogs trifluoromethylcysteine, fluoroalkylhomocysteines, and fluoroalkylcysteines, and derivatives of them. These compounds are drug-candidate compounds or raw materials of drug-candidate compounds. Specifically, trifluoromethionine, trifluoromethylcysteine, a fluoroalkylhomocysteine, or a fluoroalkylcysteine is simply and conveniently prepared directly without passing through homocysteine or cysteine by adding metallic sodium to an optically active or racemic homocystine or cystine in liquid ammonia and further adding a fluoroalkyl iodide thereto under Birch reduction conditions.