Troparil is a phenyltropane-based dopamine reuptake inhibitor that is derived from methylecgonidine. It is a stimulant drug used in scientific research. The most commonly used form of troparil is the tartrate salt, but the hydrochloride and naphthalenedisulfonate salts are also available, as well as the free base.
Troparil (another name: WIN 35,065-2) is a synthetic derivative of cocaine and was synthesized during the 1970s to separate the stimulant and depressant actions of cocaine from its toxicity and dependence liability. This compound was also used as a starting material or intermediate in synthesising several 3β-phenyltropane derivatives. With a phenyl group directly attached to the tropane ring, troparil is a 3-phenyltropane.
Troparil is used in scientific research into the dopamine reuptake transporter. 3H-radiolabelled forms of troparil have been used in humans and animals to map the distribution of dopamine transporters in the brain. It is also used for animal research into stimulant drugs as an alternative to cocaine which produces similar effects, but avoids the stringent licensing requirements for the use of cocaine itself.
Troparil is a few times more potent than cocaine as a dopamine reuptake inhibitor, but is less potent as a serotonin reuptake inhibitor, and has a duration spanning a few times longer, since the phenyl ring is directly connected to the tropane ring through a non-hydrolyzable carbon-carbon bond. The lack of an ester linkage removes the local anesthetic action from the drug, so troparil is a pure stimulant. This change in activity also makes troparil slightly less cardiotoxic than cocaine.
