Process for the preparation of benzoxazine derivatives
申请人:DAIICHI SEIYAKU CO., LTD.
公开号:EP0304684A1
公开(公告)日:1989-03-01
The invention relates to a process for producing a (±)-3-alkyl-3,4-dihydro-2H-[1,4]benzoxazine derivative of formula (II) by stepwise racemization procedure.
The invention further provides a process for optical resolution through the formation of a salt between a (±)-benzoxazine compound and an optically active form of camphor-10-sulfonic acid. Without requiring the conventional expensive resolution reagents, this process not only assures production of an optically active isomer of compound (II) in high purity but also permits reuse of the optical resolution reagent.