RMAN issue while performing Active Duplicate RMAN-01009: syntax error: found "spfile": expecting one

RMAN> run{
2> duplicate target database for standby from active database
3> password file
4> spfile '+DATA/prodrep/parameterfile/spfileprodrep.ora'
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "single-quoted-string": expecting one of: "backup
RMAN-01007: at line 4 column 8 file: standard input
RMAN>