SQL & PL/SQL

I'm getting an ORA-00936: missing expression message when I run this:

EXECUTE IMMEDIATE '

select  count(*)

into '||v_is_sync||'

from (

select * from ' ||ownername ||'.'||tablename|| '@TESTREPDB where   test_sys_date>=to_date('''||et_date||''',''dd.mm.yyyy'')

minus

  select * from '||ownername||'.'||tablename||' where   test_sys_date>=to_date('''||et_date||''',''dd.mm.yyyy'')

  )  '

;

Thanks in advance for your help.