expdp using parfile and using consistent parameter

nohup expdp "'/ as sysdba'" parfile=abc.par &
---abc.par is as  below
DIRECTORY=EXPORT_TC
SCHEMAS=TC
dumpfile=file_name.dmp
logfile=file_name.log
flashback_time="to_timestamp(to_char(sysdate,'dd-mm-yyyy hh24:mi:ss'),'dd-mm-yyyy hh24:mi:ss')"