Patient will receive Dacarbazine intravenously (IV), which means it is given through a needle in a vein in the arm or through a venous port (if patient already has one). Dasatinib will be given orally starting day 2 for 17 days straight (days 2 through 19) starting the day after patient receives their first dose of Dacarbazine. The therapy will be repeated every 21 days (21 days = 1 cycle). Patient may be given other drugs before each cycle to help reduce side effects of the therapy. If patient experiences severe side effects, the amount of Dacarbazine and/or Dasatinib they receive in future cycles may be decreased.