How to configure Debian Brazilian locale

Configure your xserver, here is the xorg:
# dpkg-reconfigure xserver-xorg

My keyboard layout "us" and own variant "us_intl"
$ cat /etc/X11/xorg.conf
...
Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc104"
Option "XkbLayout" "us"
Option "XkbVariant" "us_intl"
EndSection
...

Now configure your locales and select the default:
# dpkg-reconfigure locales

Reboot your system:
# init 6