8-[(E)-2-(3,4-dimethoxyphenyl)ethenyl]-1,3-diethyl-7-methyl-purine-2,6 -dione

Properties

Safety Information

Description

In March 2013, istradefylline (also known as KW-6002) was approved in Japan for adjunctive treatment of Parkinson’s disease (PD). Istradefylline acts by antagonism of the adenosine A_2A receptor, which is colocalized with dopamine D₂ receptors in the striatum, to enhance dopamine D₂-dependent signaling. Istradefylline is a light-sensitive compound and has been evaluated in vitro under low-light conditions to prevent isomerization of the (E)-styryl group and decomposition. Istradefylline has a Ki of 2.2 nM for the rat adenosine A_2A receptor and an ED₅₀ of 0.03 mg/kg, po, in reversal of haloperidol-induced catalepsy in mice. Further characterization showed istradefylline to have a Ki of 12 nM for the human adenosine A_2A receptor, to be highly selective, and to be a functional competitive antagonist. Istradefylline has activity alone and in combination with levo-dopa in preclinical animal models of PD. The synthesis of istradefylline was accomplished by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-mediated coupling of 5,6-diamino-1,3-diethyluracil with 3,4-dimethoxycinnamic acid, followed by cyclization upon treatment with aqueous NaOH, and selective methylation (MeI, K₂CO₃, and DMF).