Get error in SQL query for update in one table from two tables

update table_one a
from table_two b , table_three c
set a.aprl_to_dt= b.aprl_fr_dt1,
a.aprl_fr_dt =  max(c.aprl_entdt) 
where b.aprl_cmpcd='01' and b.aprl_flag='CNF' and b.aprl_status='ECNF'
 and (b.aprl_fr_dt1 is not null or b.aprl_fr_dt1 !='')
 and b.aprl_cmpcd =a.aprl_cmpcd
and b.aprl_flag=a.aprl_flag and b.aprl_status = a.aprl_status
and b.aprl_empcd= a.aprl_empcd and b.aprl_due_dt = a.aprl_due_dt 
and b.aprl_empcd = c.aprl_empcd and b.aprl_cmpcd = c.aprl_cmpcd and b.aprl_due_dt = c.aprl_incdue
group by  b.aprl_empcd, b.aprl_fr_dt1, b.aprl_to_dt1;

update table_one a
from table_two b
set a.aprl_to_dt= b.aprl_fr_dt1,
a.aprl_fr_dt in (select max(c.aprl_entdt) from table_three c where
 b.aprl_empcd = c.aprl_empcd and b.aprl_cmpcd = c.aprl_cmpcd and b.aprl_due_dt = c.aprl_incdue
group by  b.aprl_empcd, b.aprl_fr_dt1, b.aprl_to_dt1)
where b.aprl_cmpcd='01' and b.aprl_flag='CPL' and b.aprl_status='ECPL'
 and (b.aprl_fr_dt1 is not null or b.aprl_fr_dt1 !='')
 and b.aprl_cmpcd =a.aprl_cmpcd
and b.aprl_flag=a.aprl_flag and b.aprl_status = a.aprl_status
and b.aprl_empcd= a.aprl_empcd and b.aprl_due_dt = a.aprl_due_dt

_US09C8 line 1, Syntax error on 'in'.  The correct syntax is:
    UPDATE table [alias]
       [FROM table {, ... }]
       SET column = expression|NULL {, ... }
       [WHERE search_condition]
     or:
     UPDATE table [alias]
       [FROM table {, ... }]
       SET (column,column,...) = (SELECT expr,expr,... FROM ... )
       [WHERE search_condition]