6-chloro-3-methylpyrimidine-2,4(1H,3H)-dione, 3-Methyl-6-chlorouracil; 6-Chloro-3-methylpyrimidine-2,4(1H,3H)-dione, 3-Methyl-6-chlorouracil, and 6-Chloro-3-methylpyrimidine-2,4-dione;