Methiopropamine

Methiopropamine

Systematic (IUPAC) name
1-(thiophen-2-yl)-2-methylaminopropane
Clinical data
Legal status	DE: Anlage I (Controlled) UK: Temporary Class Drug Illegal in China, Finland, Florida
Identifiers
CAS Number	801156-47-8 N Template:CAS (hydrochloride)
ATC code	N06AA
PubChem	CID: 436156
ChemSpider	385727 Y
Synonyms	MPA; Methiopropamine; Methedrene; Syndrax
Chemical data
Formula	C8H13NS
Molecular mass	155.261 g/mol
SMILES CNC(C)CC1=CC=CS1
InChI InChI=1S/C8H13NS/c1-7(9-2)6-8-4-3-5-10-8/h3-5,7,9H,6H2,1-2H3 Y Key:HPHUWHKFQXTZPS-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

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.

Pharmacology

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.

Metabolism

Methiopropamine metabolism is somewhat similar to methamphetamine. Hydroxylation, demethylation and deamination are in common. Formation of thiophene S-oxide is different, as is the end product which will probably be (substituted) thiophene-2-carboxylic acid. It is then excreted in urine. Compounds on red are inactive.

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.

Synthesis

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.

Four-step synthesis of racemic methiopropamine from (thiophen-2-yl)magnesium bromide.

Legal status

China

As of October 2015 MPA is a controlled substance in China.

Finland

Methiopropamine is illegal in Finland.

Germany

Methiopropamine is explicitly illegal in Germany.

United Kingdom

Following the ban on ethylphenidate authorities noticed an increase in methiopropamine use by injecting users. The ACMD suggested it be banned on 18 November 2015 as it had similar effects to ethylphenidate. The government enacted a temporary drug control order a week later which came into force on 27 November 2015.

United States

Methiopropamine is not scheduled at the federal level in the United States.

Florida

Methiopropamine is a Schedule I controlled substance in the state of Florida making it illegal to buy, sell, or possess in Florida.

See also

• α-Pyrrolidinopentiothiophenone (α-PVT)
• Thiopropamine, demethylated counterpart
• Propylhexedrine, another ring substituted stimulant used as over-the-counter decongestant
• Thiothinone