Pharmacodynamics The result of the 3,4-dichlorination on 3,4-DCMP is a higher selectivity for the serotonin transporter and serotonin uptake inhibition. Serotonergic activity among phenidates is very rare, and 3,4-DCMP is one of only three compounds from this class with appreciable serotonergic activity, the other two being
HDMP-28 &
HDEP-28. The reason for the serotonergic activity of all three compounds is a bulky aryl ring system (in the case of the aforementioned compounds, a 2-naphthalene ring), which mimics the bicyclic
indole ring system of serotonin. Examples of compounds with the same SAR modifications done to increase serotonergic activity include
naphthylaminopropane and
3,4-dichloroamphetamine. The 3,4-dichloro group also increases resistance to
metabolism, which can be seen on the compound's greatly increased duration of action and
biological half-life. Furthermore, it also results in a greatly increased affinity for both the dopamine and noradrenaline transporters, because the 3,4-dichloro group more closely mimics the 3,4-dihydroxy group found on dopamine and adrenaline. Examples of compounds with the same SAR modification done to increase affinity to DAT & NET include
dichloropane and
O-2390.
3,4-CTMP, the d,l-threo diastereomer of 3,4-DCMP, is approximately seven times more potent than methylphenidate in animal studies, but has weaker reinforcing effects due to its slower onset of action. However, H. M. Deutsch's discrimination ratio implies it to be more reinforcing than
cocaine. • 1 This is an abbreviation of the d,l-erythro diastereomer of 3,4-DCMP. • 2 This is an abbreviation of d,l-threomethylphenidate, more widely known by its brand name
Ritalin. == Legality ==