I bought a ringtone in itunes and cannot get it to sync with my iphone. Help please

I just spent 3 hours trying to figure out how to do the same thing with lots of confusing attempts. The ringtone shows up in my iTunes Library under Tones, but when I sync it doesn't go into my phone.

Until I just figured out this. View pull down menu has a tab for View Side Bar. The Side Bar has a Library folder for Tones and a Device folder for Tones. They don't automatically show up in both places like Music seems to for some reason.

I clicked on the Library Tones folder. Then drag (copies) the actual ringtone file from that folder screen on to the Side Bar Device Tones folder. Now the ringtone shows up in both places and instantly syncs from that itunes device folder into my iphone settings sounds ringtone options.