The validity of the following synthesis has been debated here for quite some time now:
http://rhodium.lycaeum.org/chemistry/anthranilic.txt
So Dr. Dream picked up those small glass jars he had in the fridge and begun to play. The crappy product from “Test #2” was soon discarded, that run was fucked up good. The second runner up product from “Test #1” was another story. First a simple recrystallization from a dH2O/EtOH mixture, then recrystallization from the same type off mixture but with decolorizing carbon present (about 300mg). This was messy; Dr. Dream has not been working with carbon in quite some time.
The result from “Test #1” was 6.24g nice glistering flake-like crystals, even though they looked nice the colour was not so nice, like “brown sugar” (not heroin
![Wink ;)](https://thevespiary.org/talk/Smileys/default/wink.gif)
. Sloppy carbon usage technique, I believe. More correctly the individual crystals were a bit like needles, but they formed flakes by grouping side-by-side.
The product from “Test #3” was worked up in similar manner, but the first recrystallization was omitted. The result was 6.83g of product that looked exactly as the one described above. No doubt it was the same thing.
In both cases the product was allowed to dry for 24 hours on a glass dish in room temperature, prior to weighting and further procedures.
In retrospect, knowing more than the reader does so far, I think the best thing is to; perform the Step-by-step in my “last paper”, when the non reacted phthalimide precipitates add some (2-300mg) decolorizing carbon and see what happens. Then filter and proceed, use the product for The Next Step without yield lowering post synthesis purification.
The Next Step:
The first 6.24gs was placed in a 100ml RB flask. 5.0ml Acetic Anhydride was added, 4.7ml would have been 1:1, but it was an old bottle, the air is not dry this season and so on. Just after the entire dry material had turned damp, things went really hot, there was a reaction going on for sure! I “stirred” with a glass rod; no external heat was applied, after half an hour of doing this, things had cooled down. The slightly gray product looked dry but the smell of Acetic Acid was strong. Left it in room temperature for 24 hours, after this most of the Acetic Acid smell was gone.
In a similar manner the 6.83gs with origin from “Test #3” was put into another 100ml RB flask ~5.5ml Acetic Anhydride was added; again this was more than enough. Things went hot, and this time external heat was applied. Everything was wetter in this run, compared to the previous one. The lightly grayish product was left overnight, but was not dry (free from Acetic Acid) when The Last Step was performed.
If the modification I proposed above is used, I assume this product will not be very pure. To make The Last Step more foolproof, recrystallization from dH20/EtOH (50/50 as invented by Cheapskate) could probably be worth the extra time and work. Anyhow, I did not purify my suspected N-acetyl-anthranilic acid after this step.
The Last Step:
To the first of the two RB flasks above was added 6.0ml o-Toluidine. As soon as this was done the RB flask was emerged in an oil bath preheated to 190°C. The reaction begun after just a few minutes, after only an hour (with the temperature held between 189-193°C) the reaction died. Another 1.0ml o-Toluidine was added and the mixture held at about 190°C for another 30 minutes. Now the mixture was poured into a 250ml beaker with 100ml 0.2% NaOH (200mg NaOH added) solution. After some hours in the fridge “the mess” was almost solid and the water was poured off. 50ml Acetone was added, and it was slightly heated to make “the mess” dissolve. 2.0ml 37% HCl was added. After a night in the fridge, no crystals, added another 1.0ml 37% HCl and about 15ml Acetone and put the beaker in the freezer (-10°C). Crystals precipitated in the same manner as I have seen before using this method. Left it there for 24 hours to ensure complete precipitation. Filtered and boiled in Acetone to get 4.34g Methaqualone that was pure enough for consumption.
To the second RB flask 6.5ml o-Toluidine was added, everything got wet (the powder was damp already, remember?). After ~10 minutes at room temperature it had solidified (!?). After this delay it was emerged in a 190°C oil bath. The temperature was about 195°C, after 30 minutes it was 220°C, by mistake (my corn-oil smoked
![Wink ;)](https://thevespiary.org/talk/Smileys/default/wink.gif)
. Brought it back down to 200°C and kept it there until the total time was 90 minutes. At the one hour point the reaction was dead though. The mixture was dumped into a weak NaOH solution in the same manner as above. This time “the mess” was a bit browner and not so much the usual purple tint, that 220°C top sure was overkill. I might add that I use a Claisen adapter on the RB flask as some kind of condenser, the water leaves just fine even with it on. It almost solidified in the fridge as above and the same method was used. Off with the NaOH solution, mixed with ~60ml Acetone and added 3ml 37% HCl, put in the freezer for 24 hours. Just as before, crystals appeared after many hours in the freezer. Again I filtered and boiled in Acetone to get 4.80g rather pure Methaqualone.
The yield in the last step was rather low (this has been the case for Dr. Dream when using N-acetyl anthranilic acid made using the KMnO4 oxidizing method too). I think the best thing to do is to recrystallize the N-acetyl anthranilic acid using EtOH/dH2O then grind the crystals to a very fine powder. After this, the powder is placed in a RB flask and 1.20mol% o-Toluidine is added and the flask swirled until all the powder is wet. Then emerge in preheated oil (~170°C), when the reaction dies at this temperature raise it fast to 190°C and keep it there until the reaction again dies.
-Methaco(s)mic
methaco_s_mic@hotmail.com (send PGP key or no reply)