Cephalotaxane derivatives and their processes of preparation and purification
申请人:Robin Jean-Pierre
公开号:US20050090484A1
公开(公告)日:2005-04-28
The present invention concerns a new general process for asymmetric hemisynthesis of harringtonines and their analogs, that are alkaloids used in chemotherapy. This process comprises direct esterification of a natural cephalotaxine with an acylating compound constituted of a side chain precursor which backbone and functionalization are entirely preformed. The invention also concerns a natural, synthetic or semi-synthetic harringtonines including their tautomeric forms and their salts of the following formula:
wherein n=2 (i.e. harringtonine) or n=3 (i.e. homoharringtonine), in which the total content of impurities, possibly including enantiomeric forms, is lower than 1%, and/or the content of the major impurity is lower than 0.9%, and/or the chromatographic assay exhibits a harringtonines content higher than 97.5%.
Process for the preparation of enantiomerically pure substituted
申请人:Bayer Aktiengesellschaft
公开号:US05306820A1
公开(公告)日:1994-04-26
(Quinolin-2-yl-methoxy)phenylacetic acids are known as inhibitors of enzymatic reactions in the context of arachidonic acid metabolism. Enantiomerically pure (quinolin-2-yl-methoxy)phenylacetic acids can be prepared in a simple manner and in high purity and yield by diastereoselective alkylation of corresponding (quinolin-2-yl-methoxy)phenylacetic acid menthyl esters and subsequent specific removal of the ester radical with acids.