Effective complexation of psychotropic phenethylammonium salts from a disodium dipyrazolate salt of macrocyclic structure

Abstract

The equilibrium stability constants (Ks) of ammonium pyrazolate complexes [L2−]2RN(R′)H2+ (3, R′ = H and 4, R′ = Me) formed from a macrocyclic disodium dipyrazolate salt 2[L2−] 2Na+ and ammonium salts (RNH3+X− or RN(Me)H2+X−) of psychotropic drugs and neurotransmitter catecholamines have been evaluated by electrochemical methods in DMSO solution. The resulting Ks values demonstrate that, except for (±)-amphetamine, the complexes formed by lipophilic primary [mescaline, (+)-amphetamine, (±)-p-methoxyamphetamine (PMA), (±)-3,4-methylenedioxyamphetamine (MDA)] and secondary [(±)-methamphetamine, (+)-methamphetamine and (±)-3,4-methylenedioxymethamphetamine (MDMA ‘ecstasy’)] phenethylamines are more stable than those formed from hydrophilic ones (dopamine and norepinephrine). A 1H and 13C NMR study on the formation of complexes of structure 3 and 4 formed from primary [mescaline, (+)-amphetamine] and secondary [(+)-methamphetamine] ammonium salts is given.