Barbital barbiturate drug, molecular model. Barbital (also known as barbitone) is a type of barbiturate, a class of drugs that act as sedatives on the central nervous system. It was marketed under the brand name Veronal and used as a sleeping aid (hypnotic) for insomniacs from 1903 to the mid-1950s. Barbital's chemical formula is C8H12N2O3. Atoms are represented as spheres and are colour-coded: carbon (C, grey), hydrogen (H, turquoise), nitrogen (N, blue) and oxygen (O, red).