申请人:Alcon Laboratories, Inc.
公开号:US05151544A1
公开(公告)日:1992-09-29
Disclosed is a process for the synthesis of enantiomerically pure R and S isomers of 2,7-difluoro-4-methoxyspiro[9H-fluorene-9,4-imidazolidene]-2',5'-dione from 2,7-difluoro-4-methoxyfluorenone. Intermediate amino acid esters and urea esters and their preparation are also described.
本发明公开了一种从2,7-二氟-4-甲氧基芴酮合成对映纯R和S异构体的2,7-二氟-4-甲氧基螺[9H-芴-9,4-咪唑啉]-2',5'-二酮的方法。同时还描述了中间体氨基酸酯和脲酯及其制备方法。