The location is:
All configurations files must have the extension
.conf, otherwise they will be ignored by Nignx.
Once you place your configuration file in the correct location issue:
This will help you identify any errors in your files. If/when everything goes well just:
service nginx reload
Sometimes one needs to edit the vhost file, moving the last include some lines up in order to get the custom rewrites correctly processed:
ee site edit domain.com