Nginx - Wordpress in a Sub-directory

I am running wordpress in a sub-directory /wordpress, I want it to be served at root. I cannot change the application root to /wordpress, because i have a core php application at root, which runs as example.com/some_file.php . My configuration file run wordpress homepage and other pages fine, but wp-admin pages are broken, also any images put in wp-content folder are broken when called from within the theme. My configuration file for rewrites is:

location = / {
try_files $uri $uri/wordpress /wordpress/index.php?$args;
}

location /wordpress {
    index index.php;
    try_files $uri $uri/ /wordpress/index.php?$args;
}
location ~ \.php$ {
  try_files $uri =404;
  include fastcgi_params;
  fastcgi_pass php;
}

code

The link to my site is this and link to wp-admin is here