Try
Update myTable SET CREATED_DATE='2017-05-08 09:17:07' WHERE E_ID=9270002
Note that the date cannot be interpreted as anything other than 8th May 2017. I also think if you are going to use "AM" in the time there should be no space. Personally I think 24hr format is best.
For more information see
Understanding Oracle SQL Date Format Made Easy[
^]
[UPDATE]OP is reporting an error.
Try
'2017-MAY-08 09:17:07"
instead. Or try
TO_DATE(
'May 8, 2017, 09:17 A.M.',
'Month dd, YYYY, HH:MI A.M.',
'NLS_DATE_LANGUAGE = American')
Reference:
TO_DATE[
^]
Otherwise look to the link I provided for more ideas