Process for S-metoprolol via oxazolidin-2-one
    5.
    发明授权
    Process for S-metoprolol via oxazolidin-2-one 失效
    通过恶唑烷-2-酮的S-美托洛尔的方法

    公开(公告)号:US5034535A

    公开(公告)日:1991-07-23

    申请号:US529712

    申请日:1990-05-30

    摘要: A process for preparing S-metoprolol of the formula ##STR1## or a salt thereof, with high enantiomeric purity, is described, whereby a (S)-5-hydroxymethyl-3-isopropyloxazolidin-2-one sulfonic acid ester of the formula ##STR2## is prepared, and further reacted with 4-[2-methoxyethyl]phenol of the formula ##STR3## and the resulting intermediate of the formula ##STR4## is hydrolysed to S-metoprolol, and whereby the (S)-5-hydroxymethyl-3-isopropyloxazolidin-2-one sulfonic acid ester of formula II is prepared by reacting (S)-3-isopropylamino-1,2-propanediol of the formula ##STR5## with a chloroformic acid ester of the formula ##STR6## wherein R' is an alkyl group having 1-3 carbon atoms or a phenyl group, to the formation of (S)-5-hydroxymethyl-3-isopropyloxazolidin-2-one of the formula ##STR7## which is reacted with an activated sulfonic acid of the formula ##STR8## wherein R" is an aryl group such as tolyl and X is a halogen such as Cl, to formation of the ester of formula II, which when required is enriched with the (S)-enantiomer by crystallization.