|Systematic (IUPAC) name|
|Legal status||Unscheduled - Possible Schedule II Analog (US)|
|Mol. mass||155.261 g/mol|
| (what is this?)
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.
For N-alkyl amphetamines deamination and N-dealkylation are the major elimination pathways and renal excretion is a minor one. Thiophene 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 should be 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.
Methiopropamine is not explictly a controlled substance, however its legal status under the Federal Analog Act is not certain. It may be considered an analog of methamphetamine for legal purposes, although its structure differs more than previous successful prosecutions under the same law. It is explicitly illegal in the state of Florida and in Germany.
- Thiopropamine, demethylated counterpart
- Propylhexedrine, another ring substituted stimulant used as over-the-counter decongestant
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