Thozalinone (USAN) (brand name Stimsen; former developmental code name CL-39808) is a psychostimulant that has been used as an antidepressant in Europe.

[1][2][3][4][5] It has also been trialed as an anorectic.

[6] Thozalinone is described as a "dopaminergic stimulant",[7] and likely acts via inducing the release of dopamine and to a minimal extent norepinephrine; similar to analogue pemoline, it is reportedly devoid of abuse potential unlike other dopaminergic psychostimulants.

[2][7][8] Sodium hydride is used as a strong base to abstract the alcohol proton in ethyl mandelate [774-40-3] (1); addition of the oxyanion to dimethylcyanamide [1467-79-4] gives the intermediate (2).

Intramolecular cyclization then occurs giving Thozalinone (3).