Slightly off your question but you should really look into applying your UA miles towards Lufthansa's Miles & More program. Since you fly in paid business class you would get 2x Program and STATUS miles. So 50,000 miles = 100,000 STATUS miles (Senator level) on LH. In addition, above 35,000 miles you receive an add'l 50% uplift on both program and status miles. So 50,000 actual flight miles in paid business class on UA or any other StarAlliance partner would yield (in the best case) 116,250 miles (Status and Program). I think that LH flies direct from PHX-FRA (3 times a week anyway), then connect to BRU?