2C (2C-x) is a general name for the family of psychedelic phenethylamines containing methoxy groups on the 2 and 5 positions of a benzene ring. Most of these compounds also carry lipophilic substituents at the 4 position, usually resulting in more potent and more metabolically stable and longer acting compounds. Most of the currently known 2C compounds were first synthesized by Alexander Shulgin in the 1970s and 1980s and published in his book PiHKAL (Phenethylamines i Have Known And Loved).