Methiopropamine

Methiopropamine (MPA) is a thiophene ring-based structural analog of methamphetamine originally reported in 1942. Chemically it is not a phenethylamine or amphetamine and is not their functional analog either. It originally appeared for public sale in the UK in December 2010 as a 'research chemical' or 'legal high', recently branded as Blow. It has limited popularity as a recreational stimulant. Methiopropamine (MPA) is a thiophene ring-based structural analog of methamphetamine originally reported in 1942. Chemically it is not a phenethylamine or amphetamine and is not their functional analog either. It originally appeared for public sale in the UK in December 2010 as a 'research chemical' or 'legal high', recently branded as Blow. It has limited popularity as a recreational stimulant. Methiopropamine functions as a selective norepinephrine-dopamine reuptake inhibitor that is approximately 1.85 times more selective for norepinephrine than dopamine. It is approximately one third as potent as dextroamphetamine as a norepinephrine reuptake inhibitor and one fifth as much as a dopamine reuptake inhibitor. It displays negligible activity as a serotonin reuptake inhibitor. Methiopropamine has the potential for significant acute toxicity with cardiovascular, gastrointestinal, and psychotic symptoms. For N-alkyl amphetamines, deamination and N-dealkylation are the major elimination pathways and renal excretion is a minor one.Methiopropamine is metabolized into active thiopropamine, 4-hydroxymethiopropamine and thiophene S-oxides. These N-demethylated metabolites are further deaminated by the cytochrome P450 enzyme CYP2C19 in the liver transforming them into inactive 1-(thiophen-2-yl)-2-propan-2-one which can be seen as a phenylacetone derivative. Thiophene-2-carboxylic acid is the final major metabolic product. It is very hydrophilic and is excreted in urine. Methiopropamine and especially thiopropamine are also excreted renally, unchanged. There is a four-step synthesis of methiopropamine. It begins with (thiophen-2-yl)magnesium bromide, which is reacted with propylene oxide, yielding 1-(thiophen-2-yl)-2-hydroxypropane which is reacted with phosphorus tribromide, yielding 1-(thiophen-2-yl)-2-bromopropane which is finally reacted with methylamine, yielding 1-(thiophen-2-yl)-2-methylaminopropane. As of October 2015 MPA is a controlled substance in China. Methiopropamine is illegal in Finland.