METHOD #1: [101, 103]~Before a chemist attempts this procedure she should read both of the referenced articles to understand why Strike has included a hybrid apparatus like the one shown in figure 14.
Into the reaction flask is added 912g crystalline guaiacol and 1500g regular 48% HBr which is then slowly heated to reflux. The tepid water condenser is there to allow the bro-momethane that is formed to leave the reaction flask but is still 'cold' enough to keep the other reactants in the reaction flask. The noxious bro-moethane condenses in the cold water condenser and drips into the chilled methanol in the collection flask. This will keep this bromoethane trapped so that the chemist will not die
from breathing said gas. The reaction refluxes for 4 hours during which time the temperature that registers directly above the warm condenser should be about 95°C. When the temperature starts to climb beyond 95-97°C then it is time to stop the reaction. Some water and a little guaiacol will be lost during the reaction but that is ok because guaiacol is so cheap that the chemist couldn't care less. The reaction flask contents should take on a slightly pink color. The reaction mix is extracted hot with 2X 1L toluene and both the toluene and water layers saved. The toluene layer is distilled to remove any water that it may have absorbed and, upon cooling, will afford a crop pyrocatechol crystals which can be separated by vacuum filtration. Reduction of the toluene volume by distillation will afford a second crop of catechol.
That aqueous layer that was saved can be removed of most of its water by vacuum distillation, allowed to cool slightly then extracted with hot toluene. When the toluene cools, a few hundred more grams of catechol will crystallize out but will be contaminated with some heavy red bromo compounds. The crystals are filtered and vacuum distilled such that the pyrocatechol will distill over first, leaving the higher boiling bromo compounds behind. Yield is about 80% or 600g of catechol.
Technically, the chemist could avoid the complex glassware apparatus of this procedure for a more crude approach . This report shows some dudes de-methylating an amphetamine with concentrated HCI in a pressure cooker. A similar approach with good yields was also employed in ref. 83 and should work as well or better on guaiacol. Hydroiodic acid or hydrobromic acid will work better than hydrochloric acid but, you know, whatever floats the chemist's boat. To do this the chemist can just plain reflux HI or HBr with the guaiacol for a few hours and process as before or she can use HI, HBr or HCI and place the reactants in a pipe bomb for a few hours.
METHOD #2: [105 p725, 106-108]-This is super easy and uses aluminum chloride (AICI3) for which there are many uses in underground chemistry. The original reference is in German but the master here has translated it for you. There's something about nuclear winter or body parts at the beginning of the article. Strike is not exactly sure. But later on comes the procedure.
The apparatus to use is the reflux apparatus with drying tube seen in fig. 7a. A tube needs to be led from the top of the apparatus to a water trap because HCI gas will be evolved. 50g of guaiacol is placed in the reaction flask and heated slightly to make it liquid. Then, with stirring, 50g of anhydrous AICI3 is gradually added causing a vigorous reaction to begin. When the addition is complete the reflux configuration is attached and placed into a 210°C oil bath atop the stirplate. After two hours of reflux, the flask is allowed to cool down which will cause the catechol to crystallize. It is a good idea to dilute this solution with some 0.5M HCI and then stir or shake the flask so as to break up the crystalline mass. Next, some toluene or benzene is poured into the flask and heated so that the catechol dissolves into the hot solvent. The solvent layer is separated, cooled and processed as usual to yield catechol (70%).
METHOD #3: —1 part guaiacol and 2.5 parts Me3SiSNa in 1,3-dimethyl-2-imidazoline heated at 185°C in a sealed pipe bomb gives 80-96% catechol.
METHOD #4: [110, 111] - guaiacol and cupric perchlorate (Cu(CI04)2)-ascorbic acid (that's vitamin C, bubba!) are mixed in an appropriate solvent under oxygen atmosphere in a flask to give about 30% catechol.
PYROCATECHOL FROM PHENOL
There are a lot of bad conversion recipes for phenol and a few so-so ones. This doesn't matter because phenol is about as cheap and common as dirt. This means that the chemist can experiment with it at her leisure.
METHOD #1: —5g phenol in dHzO is stirred 5 hours at 20°C with some ferric sulfate (Fe2(S04)3, an additional 7ml_s dH20, 13mLs 6% H202 and a 'pinch' of aluminum oxide (Al203). Yield of catechol is 2.5g (50%).
METHOD #2: -Phenol can be oxidized with either performic, formic or acetic acids to catechol. For example: phenol, formic acid, concentrated H202 and polyphosphoric acid are heated 2 hours at 80°C to give 53% catechol. Addition of phosphorus pen-toxide (P205) is said to increase the yield.
METHOD #3: ~Phenol and 30% H202 in molar ratios of 10:3 to 10:8 is heated at 70°C for 8-10 hours to give -15% catechol. Addition of tert-butyl alcohol increases the yield.
METHOD #4: —80% phenol in aqueous H2S04 solution of pH 3 is brought to 50°C. 30% H202 is then added causing an exothermic reaction and a temperature of 15°C over 3-4 minutes time. 6% aqueous H2S03? is added after 4.5 minutes, the solution quickly cooled and extracted with isopropyl acetone (Strike would think that another solvent like methyl ethyl ketone could be used) to give 60% catechol.
One of the problems with all the current phenol conversions is that a certain amount of other phenols, such as resorcinol and hydro-quinone, will be formed along with the catechol (don't ask). These species are very hard to separate from the catechol because they are all so similar. Aside of carefully monitored fractional distillation there are some vague strategies which can be found in the Chemical Abstract references 116-118.
Wow! How did Strike go from such detailed articles to this load of crap about phenol conversion? Well, it's probably because Strike has never had to stoop so low as to need these methods nor should anyone else these days. These recipes are for the desperate peoples of the future to ponder. Although by then they will have starfleet replicators to do their bidding.
Future drug user: "MDA!! 100mgs" Computer voice : "Affirmative."
With catechol in hand there are many ways to proceed as one can see from the genealogy chart. Strike feels it's best just to dive right in and discuss the most pivotal point of all that makes X what it is: that little bridged ring structure stuck on the benzene core. When the two OH groups of catechol are bridged, the species that is borne can be named either methylenedioxy benzene or, as the Chemical Abstracts call it, 1,3-benzodioxole. Why '1,3-'? Well, the carbon that bridges the two oxygens is now counted as the #2 carbon. Later, when the chemist adds something to the 1,3-benzodioxole, all the numbers change-again and the #2 carbon will no longer count. Isn't chemistry confusing? There is one very important thing that there should be no confusion about. That is that if one were to demethylate eugenol to get allylpyro-catechol, demethylate vanillin to protocatechualaldehyde, or acquire any species that has those two adjacent OH groups then those molecules can be methylenated just like catechol with similar yields. One needs to remember to adjust for the weight differences of the different species one wants to methylenate.
The reaction itself works by the action of Na or K from NaOH or KOH which form what is called a catechoxide dianion with the two OHs of the catechol species. This makes the two ripe for an attack by a methylene halide which can be either DCM (methylene chloride, or dichloromethane), DBM (methylene bromide, or di-bromomethane) or DIM (methylene iodide, or diiodomethane). DCM is cheap and works pretty well, but DBM and DIM work better yet are more expensive.
METHOD #1: Methylenation started out in the first part of the century using a process pretty much like the following , 55g pyrocatechol, 200mL dH20, 40g KOH, 140g DCM and 125mL ethanol are heated in a sealed pipe bomb at 120°C for 24 hours. The solvent is then distilled off and the 1,3-benzodioxole can be extracted from the remaining water solution using benzene or ether and the solvent layer fractionally distilled to afford 1,3-benzodioxole (yield=20%).
There are other articles that have shown that this sort of reaction mix will work just as well under simple reflux rather than a pipe bomb , A mixture of 220g catechol, 272g DCM (or a proportional amount of DBM or DIM), 220g potassium hydroxide and 1L ethanol is refluxed in the hood for 72 hours, cooled and the brown-colored solution vacuum filtered. The filter cake is washed with a little ether, which is combined with the other filtrate, and the solution is distilled to remove all the solvent. The residue that is left will have 500mL ether, 1L dHzO and 200mL 20% aq. NaOH solution added to it and the whole thing stirred really well for a few minutes. You may or may not recognize what's going on here but it is the exact sort of thing that one uses to get the eugenol out of sassafras oil. Any exposed OH groups (catechols) will form those anions with the Na from the NaOH and bring the catechol into the water as a solid. Any converted 1,3-benzodioxole or methylenated compound will not have any such exposed OHs because they will have been tied up by the successful conversion. This means that such molecules will remain in the solvent layer. This is an excellent way to purify any of the methylenated compounds produced by any of the following methods. The ether layer is separated, washed with water and distilled to give 1,3-benzodioxole in about 26-32% yields.
METHOD #2: Later versions of methylenation get the yield up to 50% by employing the use of a catalytic metal called Tobin bronze , The chemist can buy this or make it herself (yeah, right) by mixing or smelting or whatevering 60% Cu, 38% Zn, 1.5% Sn, 0.3% Pb, and 0.2% Fe (that all adds up to 100% by the way). 0.1M of any catechol (for pyrocatechol that's 11g), 3g of Tobin
bronze shavings and 10.2g DCM are placed in a pipe bomb which is positioned vertically in a bucket of crushed ice with the permanently sealed end on the bottom. The DCM mix is allowed to get cold, then 40mL of cold methanol is poured as gingerly as possible down the inner wall of the bomb so that as little mixing as possible between the two liquids occurs. Then a cold solution of 11g KOH (or 8g NaOH) in 15mL dH20 is added in the same manner as was the methanol so that as little mixing as possible occurs. The bomb is immediately sealed after the final addition.
All of this careful addition is to keep the reaction from starting before the bomb is sealed. It is also important to note that the chemist must scale up or scale down the amount of reactants so that the total amount of all the ingredients consumes no less than 90 of the volume space of her particular pipe bomb. Too much head space with its atmospheric air will lower the yield. The bomb is heated in an oil bath or oven at 105-115°C for 18-24 hours and the contents are then distilled with the 1,3 benzodioxole coming over at about 170-175°C with no vacuum. Alternatively, the chemist can only distill off the methanol, wash with dilute NaOH solution and extract with ether, etc.
METHOD #3: Things start to look easier and the yields higher when the following method is employed , This method uses a solvent called DMSO (dimethylsulfoxide). Maybe you've never heard of this solvent but Strike has. It is a common solvent used in all fields of science; and although Strike is not 100% sure, Strike believes that one can substitute DMF (dimethylformanilide) for DMSO.
110g catechol, 500mL DMSO, 100mL DCM and 83g NaOH are stirred in a flask with a condenser just like fig. 7a. The temperature is brought up to 120°C either by direct heat or by an oil bath. A violent reaction will start when the temperature is approached and will last for only 10 minutes. That's it! The solution is stirred for another 30 minutes and then allowed to cool. The 1,3-benzodioxole can be removed by methods similar to those of the previous two methylenation methods or one can do the superior method of separation employed by the scientists of this article.
They found that by adding water (about 500ml_) to the reaction mix and then distilling it with no vacuum, that the benzodioxole will distill over with the water at the same time as an azeotrope (an azeotrope is a term for when two things are stuck together when they distill over). The azeotrope will separate out in the collection flask to give a clear upper layer of water and a clear lower layer of oily benzodioxole. If one has made heavier oil species such as piperonal or safrole using this, then it is preferable to just straight up distill the stuff without the addition of water. The yield of 1,3-benzodioxole is 70%.
When doing this method the scientists confirmed something that has long been theorized by those who study these sorts of things. That is, they determined that if one tries to convert all of the catechol at once like was done in the above method then it tends to form a dimer side product like that shown below .
You see, if there is as much activated catechol swimming around as there is DCM to react with it then there is a greater chance that the activated catechol will react with itself and form a dimer before the DCM has a chance at it. This accounts for about 20% of the loss in yield. This was avoided by adding the NaOH and catechol in small batches to the already hot (120°C) solution of DMSO and DCM. The DCM
was allowed to have its way ^^ _CH
with substrates, then another 2
small addition was introduced, etc., until all the catechol and NaOH were added. This gradual addition strategy raised the yield to 91%! Strike is not about to explain the weird apparatus used to allow simultaneous addition of two dry products to a hot, sealed system. If a chemist wants to try gradual addition then her best bet would be to drop the stuff down through the condenser and wash down anything that sticks to the inner wall of the condenser with a few squirts of DMSO.
You do believe Strike when Strike tells you these things, don't you? No? Well neither does Strike. But fortunately for us, some-
one did. And now that person, Merlin, has schooled us all. Check out Merlin's adaptation of #3:
"Methylenation for Beginners
By far the best method I have tried to produce benzodioxole in terms of yields and simplicity. In comparison to other processes, this is in fact quite fun and I'll explain it in a fashion that can be followed by a complete novice, like I was when I started a while ago. What we do is react and reflux the ingredients first, then use a simple distillation procedure to extract the product with water as an azeotrope. Once extracted we wash until the product is clear, and then separate. From start to finish it will take about six hours.
Stage one - the reaction happens in the form of a reflux with a dry set-up. You will need a 2000ml reaction flask, a condenser and a drying tube packed with calcium chloride or other drying agent. The reaction needs to be stirred in a big way, so before we add the ingredients make sure you have a clean stirrer bar ready, I prefer the eggy shape bars as they tend, to be less noisy.
Catechol - 110g
Sodium Hydroxide (AR Grade) - 83g
DMSO - Dimethylsulphoxide is a very common solvent with a freezing point of 20 degrees. When you buy this stuff it will be crystallised in the bottle. To melt, all you need to do is place the bottle in a bowl of hot water for 30 minutes - simple. If you're lucky enough to live somewhere warm it may already be liquid, where I live, no chance. When you open the bottle you will notice that this stuff smells a bit farty, don't worry too much, it doesn't get that bad. 500ml straight into the reaction flask and start the stirrer. -218-
DCM - Dichloromethane 100ml pour into the reaction flask with the DMSO.
On one occasion I dried the two solvents with Sodium sulphate, I'm not sure if this affected my yields, but if it's very humid where you live then this would be a good idea. It certainly wouldn't harm if you want to be thorough.
Catechol - 110g, smells like hospital toilets from where I'm sitting. Easy and cheap to purchase. Use a funnel to get this into the flask and don't try to dissolve it first as it just sticks to everything, a dry funnel and add slowly so as not to stop the stirrer bar. When this is added the solution will start to change to a dark greeny colour. It is important that the stirrer keeps spinning, if it all stops moving in there, some bits can get left out of the reaction, and your yield will suffer.
Sodium Hydroxide - 83g of AR grade is added in the same way as the catechol. This will slow the stirrer down loads so add slowly, now the reaction flask will start to get warm as the magic starts.
Now connect the condenser and the drying tube. An important point here for beginners is to make sure the drying agent is not clumped in a big lump which can allow moisture to pass by, smash it all up with a pestle and mortar, so it completely covers the cotton wool in the drying tube. When this reaction starts in anger it is quite "happening", so if the drying tube isn't firmly placed it will blow off and shoot across the kitchen and smash. You can hold it in place for a few minutes or clamp it, or even tape it. If you're using a vacuum adapter make sure the vacuum port is blocked off properly too, once a piece of foil I'd blocked mine off with shot out in front of my very eyes, and my dog nearly ate it, so now I tape it in place.
With everything secured, start the heating gently. The reaction will already be going so things don't normally take long. After ten minutes or so the reaction will start in earnest, gases fizz out of the drying tube and the contents of the flask will be a lovely emerald green colour, this will last for three to four minutes and then gradually slow down. You may notice the smelly DMSO, a good opportunity to fart and blame it on the chemistry, if you don't have a dog to blame, like I do. Once things die down take note of the time and leave for half an hour. The next thing we will do is add 500ml of distilled water, so we need it all to cool down.
Remove the condenser, then with the aid of a funnel add the water slowly, keep stirring. If the solution is too hot the water will evaporate and make a big mess. As the water is added you will notice that loads of stodgy crapp will form, this is normal, connect the condenser for the distillation with a receiving flask at least 500ml in capacity.
We now have a big flask with lots of water in it, which we need to heat lots and lots. This will take a long time, and if you're impatient like me, it's best to sit down and expect to wait at least 30 - 45 minutes before anything starts to happen. What we're doing here is removing the water and our product benzodioxole together as azeotropes. Compared to other distillations I've done this is relatively easy and very satisfying. At about 85 degrees the distillate will start to come over, as it drops into your collection flask a blob of oil will appear in the middle of the water. The oil appears clearer than the water, which will be milky in appearance. Now all we need to do is wait, adjust the heat so the temperature doesn't go above 100 degrees, and sit down and watch TV, or have a cigarette.
After a couple of hours you may notice that what's coming over contains less oil, and eventually no oil at all, just water. That's it, you've done it. The benzodioxole will form a layer underneath the water. We just need to separate the oil with a sep funnel, wash with water twice, to remove any traces of milkiness, which I think could be sodium hydroxide, and we're sorted. Your product should be crystal clear, slightly more viscous than water, with a very strong odour, similar togasoline or benzene (petrol if you're from the UK).
The best yield I've achieved is 84g of benzodioxole from 110 of catechol. And to progress from here you'll probably need to do this reaction twice to get enough benzodioxole for the bromination."
METHOD #4: In this synthesis everything needs to be as dry as possible , The potassium fluoride (KF) should be heated at 100°C for an hour, all glassware baked at 425°F for an hour and any solvents used need to be dried through Na2S04. 152g KF, 22g catechol and 500g DMF are stirred at room temperature for a few minutes. The solution will get warm during this time and will be allowed to return to room temperature before proceeding further. 19g of DCM is added and the solution refluxed in a 110-120°C oil bath for 1.5 hours. After cooling, the solution is extracted with ether, the ether washed with water to remove any absorbed DMF, the ether dried through Na2S04 and distilled to give 1,3-benzodioxole at a yield of 98%! Using cesium fluoride instead KF reduces the reaction time and gives higher yields on the meth-ylenation of larger molecules.
METHOD #5: This last method gives super high yields and the reaction progresses at room temperature , To a stirred suspension of 12.5g sodium hydride (NaH) in 200mL hexamethyl-phosphoric triamide (HMPT) is added a solution of 28.6g catechol in 100mL HMPT over a 10 minute period. A lot of bubbling will occur, and when it dies down 80g of DIM or 52g DBM or 25.2g DCM is added and the solution stirred for 20 minutes. After 20 minutes about 500mL cold dH20 is added and the whole thing extracted with ether. The solvent layer is dried through Na2S04 and distilled to give 1,3-benzodioxole (yield=93%).
BROMINATION OF 1,3-BENZODIOXOLE
Hey, folks! We're halfway there. One can see throughout this book that bromine plays a key role in a lot of reactions. This is because it is a good nucleophile that adds well to things and helps in getting other things added. As usual, if the chemist wishes to use iodine instead of bromine that is perfectly okay. Since we are talking about bromine here, let's discuss what the bromine one needs is going to be like. What is needed here is bromine (Br2) not hydrobromic acid (HBr). Br2 is just heavy enough to be an or-angy red liquid at room temperature. If one were to take the lid off a bottle of liquid bromine then lots of red, evaporated Br2 smoke will come flying out. It isn't advisable to breathe so transfer of this stuff should be quick or in the hood. It would be best if the liquid bromine were kept cold at all times. If one cannot get liquid bromine then they can assuredly get it from the specialty gas can-nister supplier. The product of this bromination can be called 1,2-methylenedioxy-4-bromobenzene or 3,4-methylenedioxy-bromobenzene but Strike is lazy and is going to refer to it simply as bromobenzodioxole.
METHOD #1: ~143g 1,3-benzodioxole in 600mL chloroform is stirred in a flask and Br2 from a little tank is slowly bubbled through the solution over a period of 4 hours at room temperature. Ideally one wants to introduce about 190g of bromine into the flask so the chemist may wish to stop the bubbling and check the weight gain of the flask periodically. After 4 hours the solution is vacuum distilled from the flask. The first thing to come over is the chloroform, then a small amount of higher boiling, unreacted
1,3-benzodioxole, and at about 30-40°C higher should come the mother lode of yellowish bromobenzodioxole oil (yield=9l%). if one has liquid bromine then one might consider pulling the vapors that come off it into the solution using a very low vacuum pull as described in the article. The chemist may consider using acetic acid as the solvent instead of chloroform and drip liquid bromine into it as previously described [126, 127] to give about 90% yield as well.
The next two bromination recipes use recyclable bromine donors that can be used over and over again. They are called dioxane and succinimide and are more common than you think. No, dioxane is not the same as the notorious dioxin but it is still pretty toxic.
These little beauties are like bromine quarterbacks in that they take the ball (Br) and hand it off to the receiver (1,3-benzodioxole). The great thing about these two species is that they are so bulky that the only place on the benzene ring that they can hand off their Br atom with any efficiency is at the least hindered #5 carbon -223-
which is the exact one one wants the Br to be on. Once bromin-ated, the Br acts as a final deterrent to the possibility of a second bromination. As you can surmise, multiple brominations can be a problem with some methods. After releasing their bromine, both dioxane and succinimide are reformed and can be separated for reuse.
METHOD #2: [128, 129]--To make dibromodioxane one stirs 500g dioxane in a flask which is in an ice bath, all of which is in the hood. 990g of liquid Br2 is rapidly added, causing the solution to get hot (one can also bubble in an approximate amount of bromine from a gas canister). The solution is dumped into a bucket containing 2L of ice water, causing the immediate formation of a large mass of orange dibromodioxane crystals which are separated by vacuum filtration and dried.
In an ice bath a flask containing 100g 1,3-benzodioxole or catechol or guaiacol and 200mL ether is stirred and then 200g dibromodioxane is slowly added so that the heat and reaction won't get out of control. After stirring for 1 hour the solution is poured into some water and the ether layer is separated. The aqueous layer is extracted once with some more ether and the two ether fractions combined, dried through Na2S04 and distilled to give bromo-benzodioxole (90%).
METHOD #3: ~This method was perfectly tailored for the bromination of 1,3-benzodioxole. The bromosuccinimide can be purchased or made from succinimide in a way that is pretty much the same as the way dibromodioxane was made (see Ziegler, Ann., vol 551, p109 (1942)). To do this method one mixes 122g 1,3-benzodioxole, 188g N-bromosuccinimide and 500ml_ chloroform in a flask and refluxes for 3 hours. The solution is then vacuum filtered from the solids and the filter cake washed with a little extra chloroform. The chloroform wash is combined with the original filtrate and vacuum distilled to give about 180g (91%) bromobenzodioxole.
Now the real goods on BOTH of the reactions in #2 and #3. Again, courtesy of Merlin:
" Bromination for Beginners
This process will add a bromine atom onto the benzodioxole molecule which is important for the next step of the process. This is a very simple operation, and the yields are easy to achieve. There is however a downside. Brominated chemicals have a phenomenally high boiling point, which in the case of Bromo-Benzodioxole is higher than the temperature at which it will fry. Distillation will just cook your product unless you have a serious vacuum available, and by serious I mean down to at least 10mm. It took me about six attempts until I discovered what was going wrong and once I had a good vacuum pump it was an easy operation. With a vacuum of 2mm I distil this stuff at about 10CfC, and it starts to turn black at about 12CPC - 13(fC without vacuum.'
For those without a fume cupboard, proceed as below. For those with a fume cupboard, the second bromination method is recommended.
The Ingredients are placed in a reflux set-up and left for three hours. They are then vacuum filtered from the solids and then distilled with vacuum, it's quite simple.
Benzodioxole - 122g Bromosuccinimide - 188g Chloroform - 500ml
Benzodioxole - from the previous reaction, usually you will need to do twice to get the correct amounts. Washed and dried.
Bromosuccinimide - easily purchased but I could only find one grade. It's a very fluffy light orangy crystalline powder - use gloves and a mask, because bromine is VERY nasty.
Chloroform - a very common solvent which has a rather unpleasant smell. Try not to get too close to this stuff as it has anaesthetic properties which you don't really want to find out about.
There's no real order needed to get the stuff into the reaction flask. Use a 1000ml flask with a stirrer bar and it's easier if the chloroform goes in last so you can wash down the solids if you have any stuck in the funnel. Set up the condenser and drying tube as we did with the methylenation.
Start the heat and wait. It will take about 20 minutes to get going and there usually isn't much to see. The flask will be a nice orange colour from the bromine and it won't change much until just before the end. Make sure the water is running, everything is secure and leave for three hours - have a sleep or something to eat maybe.
After three hours the flask will have turned slightly darker in colour and the contents will look slightly more transparent. If so then everything is good, if not I doubt that you have anything to worry about. Allow to cool enough for the vacuum filtration, usually about 30 minutes.
Vacuum filtering can be a bit tricky, as the filter paper clogs up very quickly and stalls the process. With this stuff it is particularly important to get rid of as much of the solids as possible or your distillation be will very messy. A way round that I have found (that isn't in any book) was to use loads of filter papers, throw them all into a big beaker and then rinse them with solvent, then filter the solvent. Filter tiny amounts at a time, as soon as the paper blocks - stop and change the paper. I normally run the filtrate through at least twice. Any way you can make sure that you have done two -226-
things very thoroughly. Remove the solids from the filtrate and wash the solids with fresh solvent to get any product off the solids and back into the solvent. Save the solids that you have filtered as they can be dried and reused.
Place the filtered solvent into a reaction flask with your vacuum distillation gear ready. If you have a vacuum pump capable of getting down to the pressure needed here it will be powerful enough to strip off the chloroform without adding too much heat. If you just turn the vacuum on the evaporating solvent will cool the reaction flask until it freezes and the distillation stalls. So what you need to do is add just enough heat to get the solvent off without the temperature getting above about 20C. The solvent can be removed without vacuum, no problem with that, so long as the temperature never.goes above 10CfC (or else your product will turn black). Either way sometimes the solvent will come off orange, that Bromosuccinimide gets everywhere and the condenser will start to get really dirty and blocked.
It's obvious when the chloroform has finished coming over. If you're using heat with out vacuum the temperature will start to rise so make sure you stop before it gets too hot. If you are using vacuum it's time to stop anyway.
However well you filtered before it's time to stop the distillation and clean everything up before you distil your product. The condenser will be full of shite. Clean all your bits and replace the flask with stirring and begin to heat. As I said before if you haven't got a vacuum available that's 10mm or less don't bother.
The first few milliHtres of distillate is likely to be unreacted benzo-dioxole. This will come over at about 80°C. The best thing to do here is wait for the temperature to get to about 90° C and then stop everything, change flasks and start again. Don't allow the reaction flask to heat up while you change flasks, in fact let it cool down a bit - if you don't, you'll know why I said this.
With a new flask in place start your heating again. At around 100oc the product will start to appear. There should be loads of it, it will look very clean and clear, and could best be described as slightly yellowish in colour. If you're lucky you'll have about 180g and it will smell similar to Benzodioxole with a hint of bromine (yuckl). The bromine atom is a heavy bastard, so the molecules here weigh much more than the benzodioxole molecules, so expect a higher weight from a similar looking volume in comparison. Stop your distilling when the colour of the distillate starts to get darker in colour. What's left in the flask is shite, and can be thrown away.
The receiving flask contents should contain a very pure product. There is no need to clean up any further. For the next stage however they will need to be dhed over sodium sulphate. This can either be done now or later. Now is better, dry your product before you weigh it and place it in a screw capped bottle ready for the Grignard reaction.
This method is by far the easiest of the two methods I describe, but because it uses bromine liquid as a precursor to the dibromodioxane crystals a fume cupboard (or a fucking good method of fume extraction) is absolutely essential. Surgically removing ones gonads with a blunt knife would be a much less painful way of harming yourself than messing with this stuff in the kitchen.
The procedure is similar to the reaction described above except that dibromodioxane crystals are used instead of Bromosuc-cinimide and refluxing isn't necessary as the reaction is much easier. The dibromodioxane crystals are made quite easily and as far as I know can not be purchased.
An ice bath is needed technically but I've never had any problems with heat getting out of control. So use one anyway.
Dioxane - 500g Bromine liquid - 990g
Bromine liquid - a very nasty red liquid with a heavy vapour that shoots out of the bottle as soon as you open it, that will make your skin and eyes sting like you've never known.
Use a PP beaker, on a stir plate, in the ice bath. Slowly add the bromine which will cause the solution to get hot. The crystals will form immediately and before the whole thing gets solid pour the contents of the beaker into 2 litres of cold water. The whole thing goes whoosh! and forms a huge lump of really nice looking orange mass. There will be crystals all over the place including in the reaction beaker, and these should be carefully scraped into the water.
What's left in the water now needs to be vacuum filtered and dried. This should be done carefully and under the fume hood. Up to this point the chemistry will have taken around 30 minutes, the drying might take a day or so. Often bromine liquid stays hanging around the crystals which makes them nasty, leave in the buchner funnel of your vacuum filter overnight to get rid of all that bromine. Unless all the bromine has gone, don't go near them without a fume cupboard or a mask.
The dibromodioxane crystals are now ready for the reaction. Using the same ice bath as before we have a PP beaker containing 100g of benzodioxole and 200ml of ether, which is being stirred. We gently add 200g of dibromodioxane crystals and watch the -229 -
solution turn a gorgeous orangy red. We leave to stir for one hour.
After an hour we pour the contents into 500ml of water. We then separate with a sep funnel and extract the water layer with 50ml of clean ether. We combine these two ether layers and dry over sodium sulphate.
The distillation is the same as in the previous reaction, except there is no need to clean the condenser after the solvent is removed, as there are no solids left over from the reaction. No vacuum filtration is needed prior to the distillation either. However a vacuum of at least 10mm is still required to distil the product.
Although the clean up is much easier the yield is about the same. For those with the correct equipment this has to be the preferred method."
Now comes the mother of all chapters. Three different controlled ecstasy precursors from 1 compound: bromobenzodioxole. This is also the point that speed makers should begin to pay more attention. In the chemicals section of this book Strike has provided the recipe for making bromobenzene so that the speed chemist can make all of the analogous precursors.
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