T-SQL (SS2K8) :: Scrub Data In 5 Minute Intervals

I have a situation where I have table with over a billion records and needs to be scrubbed. Table does have a field with date time timestamp. I have been deleting rows from the table using the script below which basically provides me delete statements by date for records older than 90 days.

But now on each day row count is over 30 million rows and it takes forever to delete by date and transaction log becomes humongous.

So I would like to scrub it in 5 minute intervals instead of daily for records older than 90 days. Even in 5 minute intervals the record count tends to be around a million. This will keep the delete slice small enough to not a gigantic transaction log.

declare @startdate Datetime
declare @enddate Datetime
set @startdate = getdate()-480
set @enddate = getdate()-90

--set @vStart = select convert(varchar,@startdate, 102)

print @startdate
print @enddate

WHILE (@startdate < @enddate)
BEGIN
print 'delete from vending where DetectedDate < ''' + CONVERT(varchar(10), @startdate, 101) +''''
set @startdate = @startdate+1
END

I am hoping to modify the script above to produce a script with statements like this for a window between last 90 and 120 days:

delete from vending where DetectedDate <'6/15/2015 8:25:00 PM'
go
delete from vending where DetectedDate <'6/15/2015 8:30:00 PM'
go
delete from vending where DetectedDate <'6/15/2015 8:35:00 PM'
go