who wins the pot

we are beginners to texas no limit hold-em and the following senerio took place.Player one raises the pot 500 .player 2 who only has 150 in chips goes all in.Player three calls.After the flop player one checks,player 2 is already all in,player3 goes all in,and player 1 calls.Player 2 wins the hand with three sixes,player 3 has two pair, and player 1 has a pair.we understood that player 2 could only win the 150 he put in,but what happens to the side pot .does player 3 win the side pot because he has a better hand than player one,or does each player split the side pot because neither had the winning hand? please advise,Thank U

[xorbie]

Player 2 wins 450, player 3 wins the side pot.