1,3,5-Triazine290-87-9100 % similar Pyrimidine289-95-245 % similar 5-Chloropyrimidine17180-94-833 % similar 5-Methylpyrimidine2036-41-133 % similar Pyrazine290-37-933 % similar 5-Bromopyrimidine4595-59-933 % similar 5-Pyrimidinamine591-55-933 % similar