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Propiophenone Synthesis Essay


potted catha edulis shrub
Cathinone is a naturally occurring monoamine alkaloid with stimulant properties. It occurs naturally in the
shrub Catha Edulis (i.e. "Khat"). Illicit supplies of cathinone may be synthesized clandestinely, or prepared from actual khat. The N-methyl derivative, methcathinone, is much more common than cathinone as an illicit substance.

Cathinone was first isolated from the khat plant in the 1970's. In 1993, the USDOJ placed cathinone, and all cathinone-containing preparations (this would include the khat plant), into schedule 1 of the Controlled Substance Act. 

Methcathinone, also now a controlled substance, is the more potent, more common, N-methyl derivative of cathinone. It was first synthesized in the US in 1928 and patented by pharmaceutical firm Parke Davis in 1957. Methcathinone was used in the Soviet Union in the 1930's and 1940's as a commercial antidepressant. Methcathinone is closely related to methamphetamine and it too is easily prepared clandestinely, via the oxidation of ephedrine or pseudoephedrine, obtained from over-the-counter cold preparations.

In the last decade or so, substituted cathinone derivatives have appeared for sale as intoxicants. These
substances contain the propiophenone skeleton but with various substitutions, and are often not explicitly listed as controlled substances. These substances are usually encountered as nearly pure white or off white powders. Substituted cathinones were usually the main constituents in novelty "bath salts", unlabeled mixtures that gained a great deal of notoriety around 2010-2012, often containing caffeine and other fillers or dilutants. Most substituted cathinones are either stimulants, entactogens, or both.

There are a few substituted cathinones that are used as active pharmaceutical ingredients (API's). This includes diethylpropion, bupropion, and pyrovalerone.


propiophenone skeleton (ethyl-phenyl-ketone)
Substituted cathinones are molecules which contain the cathinone or methcathinone (propiophenone)
skeleton; inclusive of;

a benzene ring (i.e. phenyl group) linked with a propane chain; the propane chain may, or may not, be extended with anywhere from one to several additional carbons (propane to octane)

an oxygen atom bound to the beta position (carbon 1) of the propane/alkyl chain

a nitrogen atom bound to the alpha (carbon 2) position of the propane chain, this nitrogen being bound with either a lone pair (such as 2 hydrogens, or a hydrogen and a methyl or ethyl group), or incorporated into a cyclic structure (such as a pyrrolidine ring)

....along with various other potential substitutions, added onto carbons 1 through 5 of the benzene ring or attatched to the alpha backbone.

Cathinone is nearly identical in structure to amphetamine; its distinguishing feature being the oxygen atom bound at the beta carbon on the alkyl chain (i.e. beta ketone)... cathinone can also be referred to as beta-keto-amphetamine, or bk-amphetamine. Methcathinone is the N-methyl derivative of cathinone, and also the beta-keto homologue of methamphetamine.


In 1989 in Ann Arbor Michigan, an intern with Parke Davis obtained samples of methcathinone. Also obtained was the formular for its synthesis. Methcathinone use and its clandestine production would eventually become more commonplace throughout the region and elsewhere. Clandestine production of methcathinone can be acheived with easily sourced materials, and kitchen-style methcathinone labs have in recent years become relatively common. Methcathinone is prepared via the oxidation of ephedrine or pseudoephedrine with various salts; including but not limited to potassium permaganate or sodium hypochlorite. Cathinone itself can be prepared via a similar process, using phenylpropanolamine as a precursor.

Substituted cathinone derivatives can be produced by reacting a suited 2-brominated propiophenone with an amination agent (methylamine, ethylamine, etc), or, in the case of the 2-pyrrolidinyl cathinone derivatives, with pyrrolidine. Most of these unregulated substituted cathinones are produced in China, in clandestine laboratories with professional lab equipment. They are sold in wholesale quantities at relatively cheap prices, and are usually available at retail as nearly pure powders.


Cathinone and methcathinone are similar in their action to amphetamine and methamphetamine (they all target NE, 5HT, and DA transporters, enhancing monoaminergic tone), although cathinone and methcathinone have been suggested to show increased dopaminergic activity. It's unknown whether the addition of a beta ketone has a similar SAR-affect on other amphetamine compounds.

Most substituted cathinones acts as stimulants, or as entactogens, or as both; with modes of action and effects resembling amphetamine/methamphetamine (monoamine releasing agents), cocaine (monoamine reuptake inhibitors), or MDMA (serotonin releasing agents).

Effects of Methcathinone:

Methcathinone has a mode of action similar to cathinone, albeit more potent and faster acting.  It has a high affinity for the dopamine and norepinephrine transporters, while its affinity for the serotonin transporter is less than that of methamphetamine. Methcath is a dopamine and norepinephrine reuptake inhibitor (NDRI). Acute methcathinone intoxication is characterized by euphoria (some report more euphoria than methamphetamine and some report less), increased alertness, confusion or mental clouding, and sympathetic arousal; a marked by increase in cardiopulmonary output, mydriasis, sweating, anorexia, increased body temp, and sexual arousal. Mania, and paranoia are also common. The comedown which generally follows periods of heavy use is often said to be less intense than that of methamphetamine. Withdrawal is marked by severe lethargy and depression, sometimes severe.

Cathinones in Today's Drug Scene:

Modifications to the 2-amino-propiophenone skeleton have yielded a range of different compounds, similar in structure and action to methcathinone, methamphetamine, and MDMA; these are known as "synthetic cathinones", substituted cathinones, designer cathinones, or simply cathinones. The slang reference "bath salts" now seems a popular, albeit mindless, term for describing any one of the vast number of cathinone derived compounds; this creates a great deal of confusion.

It was during the early 2000's that designer cathinones started appearing for sale as quasi-legal drugs, starting, namely, with mephedrone, methylone and MDPV. By this time, there had already been established somewhat of a designer drug subculture; consisting of drug chemists, drug users, retailers. Brought together by the internet. The roster of internet-available designer drugs had for the most part been limited to psychedelics, prior to mephedrone. Phenethylamines and tryptamines. Since mephedrone in 2003, demand has grown for entactogenic and stimulant substances; more often than not, cathinones.

At present, new and/or rediscovered cathinones are appearing as others are disappearing, as anti-drug legislation advances. Legislation is becoming more broad, more ambiguous, and more preemptive in the way it is written. States like Nebraska have introduced legislation banning chemicals now not only by structural class, but by biological activity (specifically, binding affinity at a given receptor site). 

Further Reading:

PubMed: Cathinone, a Natural Amphetamine

EMCDDA Publication: Synthetic Cathinones

ACMD: Consideration of the Cathinones

Erowid/Rhodium Archive: Methcathinone Synthesis

Erowid: Methcathinone FAQ

Cayman Chemical: Today's Designer Drugs

Originally posted by Drunkguy
Why not just get alfa-methyl-styrene, make the epoxide, then react with methylamine. That would give a pair of positional-isomers, but im guessing that the ephedrine products would be preferentially formed, esp. if the conditions are right.

Because you only get a few % yield of the correct regioisomers. See a couple of posts above where the reference about the reaction of the bromohydrine with MeNH2 is described. Since it works by the same mechanism (forming first the epoxide, followed by nucleophilic ring opening), there is no reason to believe a direct use of the epoxide would be any better. Only epoxides of terminal akenes give good regioselectivity in ring opening reactions with basic nucleophiles.

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