2-pyrrolidone which is also called 2-pyrrolidone, is written "2-P" for short. The molecular formula is C4H7NO.2-P is a colorless liquid. Its solidifying poine25.6℃, flash point 129.4℃, boiling point 245℃, which is solubilize with water, low chain alcohol, low chain ether, chloroform and benzene.