if you're looking for the preposition, it's "to": drink to [or, raise a toast to, or offer a toast to] health, drink to a long life together, drink to love and happiness...

I'm assuming you already know the word "brotherhood".

Peter, I don't think "to drink to brotherhood" works in this context. "Brüderschaft trinken" means that you make close friendship with someone and have a drink to "seal" this friendship, and after that you say "you" to each other... ;o))

hat noch jemand Vorschläge?

Der Kleine Muret-Sanders