Abstract CP-I is a potent subtype-selective GABA A receptor partial agonist. Owing to its significant metabolic cleavage at C 8 observed in preliminary biotransformation studies with non-radiolabeled CP-I, the syntheses of CP-I labeled at the right or left hand side with 14 C or labeled with 3H at the right hand side were required. The two compounds labeled with 14 C at the left or right hand side were synthesized in 2 and 5 radio-synthetic steps using [14 ...
