I would like to create a friendly url for a specific file from a directory that has a long file path as well as renaming the file. I am not even sure if this is possible.
Try removing the (.+) part from your regular expression. It makes it so you need something after the brochure.pdf. Also add some boundaries:
(.+)
brochure.pdf
RewriteEngine On Options +FollowSymLinks RewriteRule ^/?eventdays-2012/brochure.pdf$ /sites/default/files/docs/fact_sheet-204499207.pdf [L]