I used Acrobat Pro for two years in my previous job, and I had learned a trick to be able to change the name of the file while it was open and I was working on it. I do not remeber how to do this, and I cannot figure it out or find the answer on the internet. This was a very useful trick.
(I remember that I would access this feature by typing something into the "Search tools" box on the right-side of the screen.)
*The answer is NOT: File > Properties > Description. When I do this, I am able to edit the document Title, Author, Subject, and Keywords, but I an not able to edit the document Name.