<> ALL works with only SELECT in sub query

Error - expecting `SELECT'
SELECT NVL(MIN(a.LOAD_ID),-1) FROM PC_JOB_LIST a
WHERE (a.sync_status is null or a.sync_status <> ALL (2,5)) and (a.job_type_code=15)

SELECT NVL(MIN(a.LOAD_ID),-1) FROM PC_JOB_LIST a
WHERE (a.sync_status is null or a.sync_status <> ALL (SELECT 2 union all SELECT 5)) and (a.job_type_code=15)