Methaqualone (Quaalude) synthesis

G.Patton

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Introduction

In this topic, you can find chemical properties and synthesis pathway of Methaqualone (Quaalude; 2-Methyl-3-(2-methylphenyl)-4(3H)-quinazolinone) from isatoic anhydride and o-toluidine with high yield. These precursor substances are quite common and do not attract a lot of attention. You can easily buy them in a chemistry store at a good price. These methods are elementary and can be easily scaled up. Don't forget about safety and use PPE.

Equipment and glassware:

  • Pear-shaped flask 10-50 ml and 100 ml;
  • Buchner flask and funnel (or small Schott filter);
  • Heated magnetic stirrer;
  • Reflux condenser (small);
  • Retort stand and clamp for securing apparatus;
  • Laboratory scale (0.01 — 100 g is suitable);
  • Pasteur pipette's;
  • Water and oil bath;
  • Laboratory grade thermometer;
  • Vacuum desiccator (optional);
  • Water-jet aspirator (optional);
  • Beakers 100 ml x2; 50 ml x2; 10 ml x2;
  • Glass rod;
  • Boiling stones;
  • Conventional funnel;
  • Filter paper.

Reagents:

  • o-Toluidine 1.1 g, 0.01 mol;
  • Isatoic anhydride 1.6 g, 0.01 mole;
  • Diethyl ether (Et2O) or acetone and distilled water ~50 ml;
  • Dichloromethane (CH2Cl2) 100 ml;
  • Petroleum ether 100 ml;
  • Acetylacetone 0.39 g, 0.0025 mole;
  • Ethanol (EtOH) 95% 30 ml;
  • Hydrochloric acid conc. (HCl) ~10 ml;
  • Methanole MeOH 50 ml;
  • Acetone 50 ml.
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Soluble in ethanol and ether. Insoluble in H2O;
Boiling Point: 406.9 °C at 760 mm Hg;
Melting Point freebase: 113-115 ̊C;
Melting point HCI salt: 235-237 ̊C;
Molecular Weight: 250.301 g/mole;
Density: 1.16 g/cm3 (20 °C);
CAS Number: 72-44-6.

Procedure

2,2'-dimethylbenzanilide (1)
A mixture of isatoic anhydride (1.6 g, 0.01 mole) and o-toluidine (1.1 g, 0,01 mol) is heated in a pear-shaped flask (10-50 ml) to 120 °С for 2 hours with a small reflux condenser in an oil bath. The reaction mixture after cooling is triturated with ether (or dissolve the brown mixture in warm acetone and add water to crash out the crystals). The resulting solid is collected by suction filtration on Buchner funnel (or small Schott filter) and recrystallized from a 50:50 mixture of dichloromethane and petroleum ether to give the intermediate aminoamide (2,2'-dimethylbenzanilide) (1): yield: 1.7 g (75%); m.p. 110 °C.
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2-Methyl-3-(2-methylphenyl)-4(3H)-quinazolinone (2)
A mixture of 2,2'-dimethylbenzanilide (0.5 g, 0.0025 mole), acetylacetone (0.39 g, 0.0025 mol) in ethanol (30 ml) containing a few drops of concentrated hydrochloric acid is refluxed for 1 h in a pear-shaped flask 100 ml. On cooling the title compound separated by filtration as the hydrochloride salt: yield: 0.59 g, (85%), m.p. 235-237 °C.
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Purification

Now begins the purification process. Put the crystals in a beaker and add roughly twice the volume of acetone, toss in a few boiling stones. They help the boil start faster and stay under control. The crystals will not dissolve, but the left over nasty-purple-stuff will. Filter the crystals and dry. If, after drying, there is a purple tint to the crystals, then recrystallize from methanol. To accomplish this, put the crystals in a small beaker add just enough MeOH to get them wet and start heating the mix. Some crystals will dissolve immediately, if they don't all dissolve bring the MeOH to a boil and add MeOH a little at a time, maintaining boiling until they have all dissolved. Now continue the boil until about 20% of the MeOH has been evaporated. Allow the solution to cool and wait. After about an hour there will be crystals forming and clinging to the sides of the tube, wait until you're sure all the crystals have formed and filter. Use acetone to wash the crystals out of your flask and to rinse as much of the nasty-purple-stuff from the crystals in your filter paper. Save both the solution and the crystals.

The recrystallization will help some, but will not purify the crystals. What has happened is that during the reaction, the nasty-purple-stuff has wrapped itself around and within the crystalline structure of the methaqualone and recrystallization will create a new surface, so an acetone wash will be able to get the rest. Now repeat the acetone boil described above, and filter and dry. You should have light steel gray to white powder, if you do, stop and put this batch aside, if you don't, do another acetone wash.

Remember the solution you saved from the recrystallization above? This is nasty-purple-stuff, MeOH, acetone and methaqualone. Put a few boiling stones in the solution and boil away half the volume. Let this set and cool, and more methaqualone will precipitate out. This can be purified with acetone as above and the result added to your completed batch. You can repeat this process until almost all the methaqualone has been recovered from the solution, but each recovery will be less pure. If you choose to do this, combine all the recovered product and do one last acetone boil to clean it up.
 
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MadHatter

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Aaaargh, you beat me to it.
But there are other routes starting with other materials. Often times the starting material will be something like toluene and methyl anthranilate or phtalic anhydride. Or even vinyl gloves.

I think the most elegant OTC route to this synth is toluene and methyl anthranilate.
Toluene to be treated with nitrating mixture of sulphuric acid/nitric acid to yield racemic nitrotoluene, which is then easily separated through freezing points yielding o-nitrotoluene. The o-nitrotoluene is then refluxed over tin with addition of HCl to yield o-toluidine.
The methyl anthranilate is available as a fragrance/taste chemical from diverse vendors in the perfume industry. It can be demethylated easily through treatment with NaOH to yield anthranilic acid, which can then be used together with the o-toluidine.

The problem with this drug is the high doses needed to achieve effect. A normal dose is around 400 mg, which makes it difficult to break even. Also, the workups a bitch, honestly, It's really difficult to achieve a pure, white end product.
 

The chef

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Aaaargh, you beat me to it.
But there are other routes starting with other materials. Often times the starting material will be something like toluene and methyl anthranilate or phtalic anhydride. Or even vinyl gloves.

I think the most elegant OTC route to this synth is toluene and methyl anthranilate.
Toluene to be treated with nitrating mixture of sulphuric acid/nitric acid to yield racemic nitrotoluene, which is then easily separated through freezing points yielding o-nitrotoluene. The o-nitrotoluene is then refluxed over tin with addition of HCl to yield o-toluidine.
The methyl anthranilate is available as a fragrance/taste chemical from diverse vendors in the perfume industry. It can be demethylated easily through treatment with NaOH to yield anthranilic acid, which can then be used together with the o-toluidine.

The problem with this drug is the high doses needed to achieve effect. A normal dose is around 400 mg, which makes it difficult to break even. Also, the workups a bitch, honestly, It's really difficult to achieve a pure, white end product.
MadHatterwhere do i find the synthesis ?
 

Uncle Lee

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The reaction looks simple, but it is a bit difficult to perform, the reaction is very difficult to clean and you will lose a batch of glass instruments.
o-toluidine is carcinogenic and very likely to cause bladder cancer and requires good safety precautions.
I don't think it is easy to synthesize pure o-toluidine, the best way is to buy the substance (if you can)
 

MadHatter

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I don't think it is easy to synthesize pure o-toluidine, the best way is to buy the substance (if you can)
Uncle LeeReally? What is the main problem with the synth in your opinion?

And yes, the methaqualone synth is messy, producing chocolate-like slurries, a lot of smell and a long and difficult work-up with a lot of yield loss. Toluene is better than acetone for purifying the crude mq.
 
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G.Patton

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G.Patton

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o-toluidine is carcinogenic and very likely to cause bladder cancer and requires good safety precautions.
Uncle Leeo-Toluidine has approximately 200 deg. boiling point, it is not much volatile liquid, but I agree with safety precautions.
 
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Uncle Lee

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Really? What is the main problem with the synth in your opinion?

And yes, the methaqualone synth is messy, producing chocolate-like slurries, a lot of smell and a long and difficult work-up with a lot of yield loss. Toluene is better than acetone for purifying the crude mq.
DocX

In fact, I can buy o-toluidine, so I have no experience in producing this substance, but when I talk to other chemists, they tell me that it is very troublesome to synthesize this substance because the reaction vessel is difficult to clean and the substance is toxic.
 

Uncle Lee

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o-Toluidine has approximately 200 deg. boiling point, it is not much volatile liquid, but I agree with safety precautions.
G.Patton
You are correct that it is not easy to inhale the vapors of this substance and cause poisoning if safety measures are good, but ensuring that the final product (Quaalude) synthesized by the chemist is free of toxic substances is difficult.
If the chemist uses the substance himself or lets others use it, he needs to make sure that the product is very pure.
 

MadHatter

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In fact, I can buy o-toluidine, so I have no experience in producing this substance, but when I talk to other chemists, they tell me that it is very troublesome to synthesize this substance because the reaction vessel is difficult to clean and the substance is toxic.
Uncle LeeReally? Because no chemists I have talked to has had any problems with this synth, and neither have I. There is a very comprehensive video on youtube also, so there's really no need for me to produce another:
I never found the cleaning of the glassware very difficult, just rinse with water, NaOH and if needed some DCM or toluene. Although focused on the racemic separation of p-toluidine through the intermediary use of oxalate, the video also shows the synth of toluidine, and if the starting material was pure o-nitrotoluene, the product would be o-toluidine also.
.
The o-toluidine is smelly and toxic at prolonged exposure, but any real cook or chemist would do this in a fumehood anyway.
But as for the methaqualone, I fully agree with the messiness. And the real work in that synth is the cleanup, as is also mentioned in the original post. The "nasty purple", or as often is the case, the nasty brown, is not acceptable and takes a LOT of work to get rid off.
There is an episode of Hamilton Morris' Pharmacopeia in which he investigates the origins of methaqualone in South Africa (which is the only country where this drug is still in widespread use), and he meets with a clandestine cook who prepares crude methaqualone in a backyard using very primitive techniques and no PPE whatsoever. He tells Hamilton about how he sometimes urinate blood ... I wonder what the levels of bladder cancer is among methaqualone users there.
 
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Uncle Lee

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I admit I am not very good at this reaction, you seem to be very experienced with this reaction, I have not synthesized o-toluidine, I was just talking to my friend about Methaqualone being difficult in purification and that o-toluidine is toxic, I said to him that potassium dichromate is also class one carcinogen and we all use it regularly, my friend told me that o-toluidine is more dangerous, especially if it is taken as an impurity in methaqualone.
 

Uncle Lee

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Since I was not interested in sedatives, I did not continue my research and experiments, I just recounted what I talked to my friend and I apologize to you for my lack of rigor.

My friend, who is in the pharmaceutical industry, told me that o-toluidine is relatively dangerous and that every year, employees of chemical plants get cancer from handling this substance because of poor safety measures, so anyone who synthesizes this substance needs to be more careful about safety
 

Hedgie

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I made Methaqualone starting with pthalic anhydride + urea to make anthranilic acid and then combined that with o-toluidine and glacial acetic acid (that’s a really rough outline, but it’s what I remember off the top of my head) to get to MQ, and I had fairly good success after work-up.
I had a good friend give me some decent advice before I did the synthesis which I credit with my success. His basic strategy was to obtain the purest starting materials he could, making sure that the anthranilic acid used is pure (it’s a white crystalline solid when pure), and to make sure that the o-toluidine is recently distilled, that it’s a clear pale yellow oil (typically when it comes from a commercial supplier it arrives as a dark red oil because it has been sitting around for a while & for our purposes this is unacceptable, so we need to take the commercial o-toluidine and distill it just prior to using it in MQ synthesis). Taking these steps prior to making it did seem to help create a reasonably clean product, although I did recrystallize the final product a couple times as well.
Methaqualone is a fairly straightforward synthesis, however, it is notoriously difficult to get all the impurities out so that it is completely safe for human use. I think someone mentioned it above already but I’ll say it again; this stuff has a reputation for causing bladder cancer because of the impurities left over from synthesis, so if you are going to be using it yourself or giving it to someone you should definitely take the time to make sure you start with the highest purity compounds you can and do a solid work-up on the product.
 

MadHatter

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Yes, the real work in this synthesis is actually before and after the synth itself. Both anthranilic acid and o-toluidine has a tendency to dark up and become full of impurities if they're not synthezised or stored with the outmost care. And finally, so does the MQ itself.
When you did the conversion from phtalic anhydride to anthranilic acid, did you manage to obtain a reasonably pale product or did it become dark and impure? This is a very common problem, and I think its very much a question of careful preparation of the hydroxide/hypochlorite reaction mixture.
 

Jack

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This thread is inaccurate the first image at the top of the page is the molecule Alprazolam, I should have been more specific but the post I made above was that in the first step of the reaction 2,2' dimethylbenzanilide isn't produced instead 2-amino-N-(o-tolyl)benzamide is produced (the amino group is not converted to a methyl group.
 

G.Patton

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This thread is inaccurate the first image at the top of the page is the molecule Alprazolam, I should have been more specific but the post I made above was that in the first step of the reaction 2,2' dimethylbenzanilide isn't produced instead 2-amino-N-(o-tolyl)benzamide is produced (the amino group is not converted to a methyl group.
JackSorry, loaded wrong pic. Fixed.
 

Midget_Impinger

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I've synthesized methaqualone many times, using anthranilic acid, o-toluidine, polyphosphoric acid and glacial acetic acid. It's pretty easy, but the part where you neutralize the mixture using carbonate..... disgusting. I mean, look at this (attached).
78C6TFevVu

I tried it twice thinking this was a failure. Then someone on SM told me that I should just continue, and it actually worked! lol.

Here's a good SM thread on it: http://www.sciencemadness.org/talk/viewthread.php?tid=156723
 

Midget_Impinger

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Also, does anyone get the annoying twitches when they take methaqualone? I quit taking it because I program for a living, and it was making it very difficult.
 

madmoney69

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Where you guys get anthranilic acid as I see its banned in china
 

Midget_Impinger

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Where you guys get anthranilic acid as I see its banned in china
madmoney69It's so easy to make.

The easiest way is to get methyl anthranilate and react it with sodium hydroxide (here). Can you check and see if you can get methyl anthranilate? It's the most common grape flavoring, and it's also used as a duck/goose repellent. But the problem with methyl anthranilate is that it's an ester of anthranilic acid. so it may be difficult to get as well..

So if you can't get methyl anthranilate, then you can make anthranilic acid from phthalimide. Here are a few videos:
And phthalimide isn't restricted at all (at least where I'm at it isn't). But if it is, just google "how to make phthalimide". It's made from phthalic anhydride or phthalic acid, which is also easy to get.

If you need to take the long route, then take a look at this NileRed video. If you follow the first 30 minutes, you'll see how you can take vinyl gloves containing either DEHP or DINP as the plasticizer, and turn that into anthranilic acid).
 
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