βk-2C-B (Beta-keto 2C-B, Bk-2C-B) is a psychedelic drug which is structurally related to 2C-B. It has been reported to have a similar effect to this drug in humans and has been used recreationally.
Conventional theory suggested primary βk-primary amines would be too prone to dimerisation to be stable in solution or when stored for long periods, but βk-2C-B.HCl is stable when kept dry. Exposure to neutral or basic aqueous solutions causes reaction to a purple solid.