2- Chloro-5 methylpyrimidine has a light yellow crystalline powder appearance at room temperature . Some would describe the color shade as off-white. It has no odor and a molecular weight of 128.56 grams per mole. Its chemical formula is noted as C5H5CIN2 and the Simplified Molecular – Input line Entry System (SMILES) as CC1=CN=C(CL)N=C1. The compound has a melting point that ranges between 89-92 degrees centigrade,and a boiling point of 239 .2 degrees at 750mm/hg. The solid is slightly soluble in water. It is typically manufactured and sold as a pharmaceutical intermediate with an average assay (purity) between 97% and 98%, the lowest noted as 95%. The density of a single mole of 2-Chloro-5-methylpyrimidine (22536-61-4) is approximately 1.169 grams per mole at 25 degrees centigrade. Enthalpy of vaporization is 45.68 KJ/mol and the vapour pressure is measured at approximately 0.0626 mmHg at 25 degrees Celsius. Common synonyms used for for 2-chloro-5-methylprimidine are: Pyrimidine, 2-Chloro-5-methylpyrimidine, 2- chloro-5-methyl-(8Cl,9Cl) and 5- methyl-2- chloropyrimidine.