Very sadly the BBC reported that two British students (aged 18 and 19) died on Monday 15 March 2010 after taking a substance called mephedrone. They were not doing anything against the law as at that time mephedrone had not been classified as an illegal substance.  It was in fact sold as a plant fertiliser. As a result of these two deaths mephedrone was rapidly made illegal in the UK. The ban came into effect on 16 April 2010.

Mephedrone is interesting both from a chemical and from an ethical point of view. 

A fertiliser?

Several websites legally advertised to sell the substance as a fertiliser before 16 April 2010. For example, plant-food.net¹ and plantfeeders. They advertised it as a plant food. Interestingly enough some of them did not seem to sell many other types of well-known plant food and they specifically stated that the mephedrone was available in crystalline form with more than 99% purity whereas most of the other plant foods were sold as solutions etc. with little importance being given to their purity.

The benefit of phosphorus, nitrogen and potassium containing fertilisers is well known. Plant food sites claimed that mephedrone causes lush growth etc. but the science quoted was very vague.  For example, the site miracle feedshad a question and answer section which contained the following:

      "Can I use Mephedrone Plant Feed on my herbs growing on my kitchen window sill?

No! Mephedrone is a research chemical which works by infinitely diluting the key molecules with pure water which helps promote plant growth. However the chemical is untested and therefore it is strictly not for human consumption or for use on plants intended for human consumption.

      Can I use Mephedrone Plant Feed on plants grown hydroponically?

Mephedrone is a research chemical which works by infinitely diluting the active molecules with pure water and   was not designed for use in such an intensive system. Mephedrone works by promoting natural and spiritual growth. Therefore we would recommend Phostrogen Plant Food for this purpose."

…so mephedrone is a ‘research chemical’ which works by infinitely diluting the ‘active molecules’ promoting ‘spiritual growth’ in plants. Not very enlightening in a chemical sense.

Another site, plantfeeders, was a little better. It stated,

"It has been shown that mephedrone directly stimulates the key complexes within plant structure that ensure that    leaves and stems are strong and mobile, enabling plants to maximise their light absorption and subsequently   increase levels of photosynthesis, yield of sugar production and ultimately promoting healthy growth.”
 

However it gave no reference to “it has been shown."

The sites did say that the product was not for human consumption. It may therefore sound cynical, but is the reason that these sites were actively promoting the sale of mephedrone in a pure form because it had become a fashionable recreational ‘drug’ for young people?

A recreational drug?

Mephedrone has street names such as “M-Cat”, “MC”, "meow meow", "plant food" and "bubbles". During the past year it had become an increasingly popular substance taken by young people (some as young as 12) at night clubs and at universities. People who took it (either by snorting or in tablet or capsule form) reported that the effects were somewhere between methamphetamine (speed) and MDMA (ecstasy).  It gives them energy, increases their heart rate and gives them a ‘feel good’ factor but is relatively short-lasting. It was an attractive alternative to illegal drugs in the UK before it was made illegal and currently there are no laws in many other countries governing its possession and use. 

Chemical structure

So what is the chemical structure of mephedrone – is it chemically similar to adrenaline and amphetamines? 

Its chemical name is 4-methylmethcathinone which is sometimes shortened to 4-MMC. It is also known as 2-methylamino-1-para-tolylpropan-1-one. It has the following structure:

It can be useful to give your students this structure and ask them what functional groups it contains and whether it does have similarities to the chemical structures of adrenaline and the amphetamines. These structures are all given on page 345 of the second edition of my IB Chemistry Course Companion.

4-MMC contains a ketone, an aromatic ring, and is a secondary amine. Note that it also contains a chiral carbon atom and it is not clear whether the drug that is sold is one particular enantiomer or a racemic mixture.

Adrenaline and amphetamines such as methylamphetamine and designer drugs such as ecstasy (see structure below) are all derived from the phenylethylamine structure (shown on the left).

It can be seen that this is essentially also true for mephedrone as the –CH₂- group next to the benzene ring has simply been oxidised to a carbonyl group (C=O). In fact apart from this difference and the fact that there is a methyl group in the 4- position (para-) on the aromatic ring the drug has an identical structure to methamphetamine (shown on the right).
It is therefore not surprising that mephedrone can mimic adrenaline and the amphetamines and cause effects such as increased alertness and a speeding up of heart rate.

Like many other drugs, mephedrone contains a basic amine group and the drug is often given in the form of its hydrochloride salt. This fits in well with topic D.9.4 on drug design for HL students studying the Medicines and Drugs option and also for both SL and HL students studying Option G: Further organic chemistry under G.8.3. It also relates to the separate page on Salt formation under novel uses for the data booklet.  

More legal highs

One of the problems that governments have is keeping up with the number of legal new synthetic drugs that are currently being made (mainly in Asia) and imported into Europe and the US.  The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) reported in 2009 that it had detected 24 new psychoactive substances through its international early warning system.

As exemplified above synthetic drugs like mephedrone can easily be designed to mimic the effects of other already banned substances. It would appear that most of these of these drugs are related either to the phenylethylamine structure of amphetamines or to cannabis related structures.

As the EMCDDA reports,

“The appearance of a large number of unregulated synthetic compounds…. specifically designed to circumvent drug controls presents a growing challenge to current approaches to monitoring, responding to and controlling the use of new psychoactive substances.”

Other legal highs also bear a striking resemblance to the structure of ecstasy.

Ecstasy is the street name of 3,4-methylenedioxymethamphetamine (MDMA) and you can see from its structure (right) that it also is a derivative of phenylethylamine.

¹ The web pages advertising mephedrone for sale were removed once the drug was made illegal in the U.K. If you want to see how one company was advertising it then I have it saved as a pdf file.