Nouveaux dérivés du pyrimido /2,1-b/ benzothiazole et leurs sels, procédé et intermédiaires de préparation, application à titre de médicaments et compositions les renfermant
申请人:ROUSSEL-UCLAF
公开号:EP0153230B1
公开(公告)日:1989-07-19
Facile Synthesis of Chiral Cyclic Ureas through Hydrogenation of 2-Hydroxypyrimidine/Pyrimidin-2(1<i>H</i>
)-one Tautomers
A facileaccess to optically active cyclic ureas was developed through palladium‐catalyzed asymmetric hydrogenation of pyrimidines containing tautomeric hydroxy group with up to 99 % ee. Mechanistic studies indicated that reaction pathway proceed through hydrogenation of C=N of the oxo tautomer pyrimidin‐2(1H)‐one, acid‐catalyzed isomerization of enamine–imine, and hydrogenation of imine pathway. In