申请人:Shionogi & Co., Ltd.
                            
                            
                                公开号:US20150166491A1
                            
                            
                                公开(公告)日:2015-06-18
                            
                            The present invention provides, for example, a compound mentioned below as a medicament for treating or preventing the diseases induced by production, secretion or deposition of amyloid-β proteins.
A compound of the formula (I):
wherein R
1
, R
2a
, R
2b
, R
3
, R
4a
, R
4b
, ring A and the dashed lines are defined in the specification,
its pharmaceutically acceptable salt or a solvate thereof.