can any one advise me on this route i cannot find a timetable on line.

Air con buses use to leave from the front of Tonys in Ayutthaya about 9 in the evening, don't know if they still do but still places advertising on the same street.

Forget the buses. Take the train. The main bus terminal relocated to the Asia Highway a couple of years ago and is a pain to get to. Plus the train is far, far safer (even if it may run a few hours late on occasions).