2,2-disubstituted 1,3-dioxolanes as antitussive agents
申请人:——
公开号:US20030176446A1
公开(公告)日:2003-09-18
(±) 3-(4-Phenyl-1-piperazinyl)-1,2-propanediol cyclic acetals, a process for the optical resolution thereof and their use as intermediates for the preparation of (−) 3-(4-phenyl-1-piperazinyl)-1,2-propanediol (levodropropizine) and salts thereof.
The present invention relates to a novel method for preparing methylene-1,3-dioxolanes of the general formula (1)
in which R
1
and R
2
have the meanings stated in the description. Methylene-1,3-dioxolanes are important intermediates for preparing pyrazoles and anthranilic acid amides, which may be used as insecticides.