I think this is a bad choice. According to most computer models, Purdue is underseeded, and should be at least a 4 and possibly a 3.
Fivethirtyeight.com shows them as the ninth most likely team to win the whole tournament. They dominated two inferior teams last weekend, Illinois and Michigan - and UALR has a slightly lower ELO and BPI rating than Michigan. Yes, the Boilers lost the Big 10 final to a highly ranked MSU team, but had two chances to take the lead or tie in the final minute, and could easily have won that game (and they did win the first game between the two teams, albeit in overtime). In the game immediately before the tournament, they beat Wisconsin by 11 at home in a game that was never in doubt. This game will be at altitude, and so depth is a factor - Purdue's much deeper than UALR, and while Purdue does have bigs who might more easily get tired, they have three of them, and can rotate them in and out easier than other teams. Purdue has also won 15 of their last 16 first round tournament games, their only loss coming in overtime; they don't usually get caught off guard in the first round (admittedly, that loss was last year).
Now that I've said all this, I'm sure Oregon State will win and Purdue will lose.