Dedutpe Table buchdurchschnittspreis2

dedupe.sql

DELETE FROM buchdurchschnittspreis2
  WHERE id in 
    (SELECT buchdurchschnittspreis2.id FROM buchdurchschnittspreis2 
      LEFT OUTER JOIN (select min(id) as id from buchdurchschnittspreis2
        GROUP BY (artnr, datum) as KeepRows 
      ON buchdurchschnittspreis2.id=KeepRows.id 
    WHERE KeepRows.id IS NULL);

Syntax error (mismatched parentheses)

DELETE FROM buchdurchschnittspreis2
WHERE id in
(SELECT buchdurchschnittspreis2.id FROM buchdurchschnittspreis2
LEFT OUTER JOIN
(select min(id) as id from buchdurchschnittspreis2
GROUP BY (artnr, datum)) as KeepRows
ON buchdurchschnittspreis2.id=KeepRows.id
WHERE KeepRows.id IS NULL);