Table of contents: MD-P2Pol & P2Pol part I A) Hydrogen Sulfates B) Alcohols From Hydrogen Sulfate C) Zwit Makes MD-P2Pol From Safrole (Maybe) D) Sacredone Dreams the Same Thing E) Acid Catalyzed Hydration F) Acid Catalyzed Dehydration G) Dehydration With KHSO4 H) Other ways to make P2Pols I) Conclusion MD-P2Pol & P2Pol part II A) Halogenation of P2Pols B) P2Ps from P2Pols A new day dawns over the rolling South Texas hill country, bee capital of Texas. The abundant and renowned peach trees of the area sweep their sweet pollen into the early morning still of the nearby hive. In an upper tier cell Benny, the beehive chemist, rubs his compound eyes and steps out of bed: Benny -- "Oh man am I bombed! Too much royal queen jelly last night. Must've blacked out at the mating rave." [Benny picks up the postage stamp-sized morning paper from the front porch and reads] "Damn killer bee attack again....Say! There's a sale going on at the 'Yellow and Black' suit emporium. Oh well ... Better get to work." [Benny is tinkering with his tiny distillation setup when Boris walks in] Boris: "Whatcha doin', Mr. Benny? Benny: "Come here kid and I'll show ya. See that golden/clear stuff in the reaction flask? That's sassafras oil that Uncle Benny bought at the health food hive." Boris: "What's that cloudy stuff in the receiving flask?" Benny: "That's water and some water soluble stuff. It came out of the sassafras oil. Even though you can't see it in the original oil, it is always there. You see that clear oil coming over now? That's mostly pure safrole. That's the stuff I'm interested in today" [Benny collects all the clear oil, leaving behind a few ml's of liquid black stuff in the reaction flask] Boris: "How do you know that what you got there is safrole?" Benny: "Because I fucking say so! That's why!" Boris: "Sniff---sniff." Benny: "Alright, settle down, kid. Here, let Benny show you how you can tell whether it's safrole or not." [Benny mixes 5g of water and 10g of H2SO4] Benny: "Lookee here. Ya see what happens when I add 10g of corn oil to this warm 70% H2SO4?" Boris: "Eww! It turned all black!" Benny: "Yup. That H2SO4 is some nasty stuff." [Benny mixes another 5g water and 10g H2SO4] Benny: "Now look what happens when I add 10g of 'safrole' to this warm 66% H2SO4." Boris: "It's turning black again, Mr. Benny. But wait! It's all bubbling and fizzing and smoking a little. What's happening, Mr. Benny?!" Benny: "There's something this oil has that the corn oil doesn't: a terminal double bond." Boris: "Huh?" Benny: "The sulfuric acid has found a shitload of molecules with which it will readily react. We see the proof of such a reaction by all that extracurricular activity of heat and bubbling. Now let me show you something else." [Benny holds up a test tube with about 15L of water in it and pours in an equal amount of safrole.] Boris: "Golly. The two don't mix, Mr. Benny! There's two layers!" Benny: "Of course. It's just oil and water. But watch when I do this..." [Benny takes a test tube out of the freezer. There's 15 mls of ice cold 66% H2SO4 in it. Benny starts to pour in 10g of cold safrole] Boris: "Don't, Mr. Benny! You're going to destroy more of your safrole....I...I....Say! The safrole is going into solution. There's no two layers. And it's only turning slightly golden-colored. What gives?!" Benny: "Here, maybe this will help clarify things." [Benny hands Boris a large packet of papers made from bee spit and plant pulp. Boris reads the title aloud...] Boris: "MD-P2Pol and P2Pol. What's that, Mr. Benny?!" Benny: "Never mind that, kid. I want you to repeat to me the name of the chemical printed on the jar that I'm holding in my hand. I bought this at the hardware store. It will allow any bee to directly aminate safrole without having to go thru any intermediate steps. In other words, one simple reaction using only safrole and this chemical is all that is required. Go ahead, kid. Say it." [Boris squints at the label, then raises up in a gesture of surprise.] Boris: "Aw shucks, Mr. Benny. That's easy! The label says...says...urk!!!" [Boris sudenly falls into an unrecuperative coma. Years of taking the neurotoxin known as LSD, plus overuse of the generally boring drug called speed, had finally caught up with him.] [Closeup of P2Pol text as it falls to the floor....] MD-P2Pol & P2Pol part I By Benny the Bee Safrole and allylbenzene are species that have a terminal double bond between the beta and gamma carbons. It is this little reactive entity that underground chemists have been using as the point of attack for amination of these species. Most methods have involved the production of a ketone (P2P) or halogen from the alkene as intermediates to final amination. The methods for making these intermediates are being overutilized and may be shut down in the future. Can a different way be found? We have learned from the Bromosafrole Page that an OH intermediate has the potential for great utility in the halogenation of safrole and allylbenzene. But let me tell ya, you have no idea how vast the utility of that OH really is. The OH species for safrole can be called 3,4-methylenedioxyphenylizopropyl alcohol or 3,4-methylenedioxyphenyl-2-propanol (MD-P2Pol), and for allylbenzene it can be called phenylisopropyl alcohol or phenyl-2-propanol (P2Pol): HYDROGEN SULFATES In the Bromosafrole Page we discussed how, under suficient concentration, HBr will add to the terminal alkene of safarole by placing its hydrogen at the terminal (gamma) carbon and its bromine at the middle (beta) carbon. This is an example of something called Markovnikov's Rule. Protic acids like HBr and HI will always add to a doublebond by allocating the hydrogen to the carbon that already has the most hydrogens on it, and the bromine to the carbon with the least hydrogens on it. In the case of safrole, the beta carbon of the double bond has one hydrogen and the gamma carbon has two: Sulfuric acid is also an H-(something) species like H-Br. It is an H-OSO2H (all that jumble of letters adds up to H2SO4. Get it!) It is a much stronger acid than HBr and will add easily to the safrole double bond. How it will add is by donating the H to the gamma carbon and the hydrogen sulfate (OSO2OH) to the beta carbon like so: .In the text"Organic Chemistry" (4th ed) by Morrison and Boyd, the authors write on page 355: "Alkenes react with cold concentrated sulfuric acid to form compounds of the general formula ROSO3H, known as alkyl hydrogen sulfate. These products are formed by the addition of hydrogen to one carbon of the double bond and bisulfate ion to the other." [Yeah, yeah! We already covered this. Get to the good stuff.] "Reaction is carried out simply [simply you say] by bringing the reactants into contact: a gaseous alkene is bubbled into the acid, and a liquid [let's say an oil for convenience' sake] is stirred or shaken with the acid." [pay attention now] "Since alkyl hydrogen sulfates are soluble in sulfuric acid, a clear solution results." Yeah, right! Well, actually, you wanna know something? It is pretty much is right In the little bee story we were seeing actual accounts of apian experiments by Benny the Bee on safrole. Clearish safrole dumped into clear water won't mix. Two layers form. But if you have a 70% or so cold H2SO4 aqueous solution and you dump safrole in, that safrole is going to disappear almost immediatley into that aq sulfuric acid layer. Why? Well, it ain't because H2SO4 is a great solvent of safrole like ether or DCM. It occurs because there is an almost immediate addition of a hydrogen sulfate to safrole. Just like the OH on the otherwise oily, nonpolar ephedrine makes that molecule soluble in water, so does it happen that a hydrogen sulfate on safrole now gives it enough H2SO4 character to allow it to go into a concentrated aq. acid solution. Talk about a lightning quick reaction with visible results! The key here is to use COLD H2SO4 and COLD safrole. A lot of us know by now that H2SO4 in high concentrations is destructive to the methylenedioxy ether bonds of safrole. It is also protically destructive to the rest of the molecule as a whole. This is a big reason why the Ritter reaction (using 98% H2SO4 and acetonitrile) is not a very good reaction to use on safrole. But, it is not for that reason alone that it fails. When this here author was wasting time on Ritter experiments, various methods were tried. The experiment always started with ice cold 98% sulfuric acid or 98% sulfuric w/acetic acid stirring away in a flask. Eventually safrole would be dripped in. It disappeared into solution immediately. Now, it has always been this author's experience that concetrated acids (especially sulfuric acid) turn safrole and any other oil black and pretty much destroys the whole lot. This is especially true if heat is applied. But when that old safrole hits the most concentrated form of sulfuric acid at freezing temperatures nothing happens. That Ritter solution would stay relatively yellow with nary a hint of browning while sitting for hours at 0 C. But when it comes time to bring that sucker to 80 C (don't ask) the whole batch turns into a nuclear meltdown cluster fuck! Yeesh! Anyway, no one is being asked to incubate their allylbenzene in 98% H2SO4 for hours to give it a hydrogen sulfate. It's a quick shake-and-bake affair.As was stated earlier, the H from H2SO4 pops onto the gamma carbon of safrole. What this does in chemical terms is create a carbocation at the beta carbon which the OSO2H will use to add itself on. That carbocation is a secondary carbocation (don't ask) which is pretty stable. Morrison and Boyd imply that it is this stability which allows one to use an inferior concentration of H2SO4 for addition puroses. They propose that 80% aq H2SO4 is an appropriate concentration for hydrogen sulfating a species like safrole. If one were under the imposition of having to add to a primary carbocation, such as one produced from ethene, then they say that nothing less than full-blown 98% conc. H2SO4 will do. What this tells us is that if we want to add a hydrogen sulfate to safrole we could use 80% aq H2SO4 with confidence. But if we really wanted to add with authority, we could jack up that concentration anywhere from 81-98%. This little process of hydrogen sulfate addition to a double bond is so ancient and simple that it hardly gets any mention in modern synthesis literature. It is such a given that Vogel's (Practical Organic Chemistry (3rd ed) only gives one mention to it as a standard little student test for alkenes (p. 241): "Reactions and characterization of ethylenic compounds (iv) Action of concentrated sulfuric acid. --(Cool 1ml amylene [Vogel's term for 2-pentene but can be any alkene] in ice and add 1mL of cold, dilute sulfuric acid (2 acid:1 water) [That's about 70% conc. folks], and shake gently until the mixture is homogeneous." Straight from the horse's mouth, folks. 'Homogeneous' means until all are one. That converted alkene goes into solution with two shakes of a 1950's organic lab student's wrist. It is interesting to finish this section with the following tidbit. Morrison & Boyd (p 350) say: "The fact that alkenes [safrole] dissolve in cold, concentrated sulfuric acid to form the alkyl hydrogen sulfate is made use of in the purification of certain other compounds. Alkanes or alkyl halides, for example [bromosafrole for example], which are insoluble in sulfuric acid, can be freed from alkene impurities by washing with sulfuric acid....a liquid alkane is shaken with sulfuric acid in a separatory funnel". Those alkene 'impurities' the doctors wish to remove from mixtures by shaking (extracting) with cold H2SO4 are actually things that you or I would prefer to save. Can you see that by shaking raw sassafras oil or, more applicable, by shaking nutmeg, dill or parsley oils, etc., with cold conc. H2SO4 one can selectively isolate small percentage allylbenzene hallucinogen precursor concentrations without distillation and convert them to a higher order precursor all at the same time! Chilling! ALCOHOL FROM HYDROGEN SULFATE So you got this ice cold mixture of MD-P2P hydrogen sulfate sitting in 70-80% aq H2SO4. Took about a minute to prepare. It can sit there cold in all that acid and eventually obliterate over time. It can be allowed to come to room temperature and obliterate even quicker. An even better idea would be to turn it into MD-P2Pol. Morrison and Boyd continue their yapping on this subject (p 349): "If the sulfuric acid solution of the alkyl hydrogen sulfate is diluted with water and heated, there is obtained an alcohol bearing the same alkyl group as the original alkyl hydrogen sulfate. The ester has been cleaved by water to form the alcohol and sulfuric acid, and is said to have been hydrolized. This sequence of reactions affords a route to the alcohols, and it is for this purpose that addition of sulfuric acid to alkenes is generally carried out. This is an excellent method for the large-scale manufacture of alcohols." That really is all there is to it. Excess water is added to the cold H2SO4/MD-P2P hydrogen sulfate mix and heated. How much heat is needed? Not that much. To see why, take a look at how Vogel ended his little student exercise (p 241): "Dilute with 2ml of water; if an upper layer of alcohol does not separate immediately [immediately?!] introduce a little sodium chloride into the mixture in order to decrease the solubility of the alcohol. Observe the odour." That boy didn't need to apply heat at all. It should be realized though that when water and sulfuric acid mix a lot of heat is generated. It is quite possible that enough heat was generated just by diluting with the water so as to cause hydrolysis. This here author never assumed such an occurrence and went ahead and boiled the stuff for 5-l0 minutes. I've got to run down the whole reaction sequence for you here. You need to get a full appreciation of how absolutely fucking fast this whole thing occurs: 1) Benny takes an ice-cold allotment of safrole and slowly pours it into a glass of ice-cold aq H2SO4 while hand-swirling the glass. (A simpler way is to magnetically stir the H2SO4 while it sits in an ice bath) [time: 30 seconds] 2) Observe, if desired, that the solution is one layer and then dump in 5X the volume of water all at once. Heat is generated. Big deal. The concentration of H2SO4 is instantly below 25% (due to dilution) where it will cause the safrole molecule little harm. {time: 5 seconds] 3) Place flask directly on a hot plate or in a pot of boiling water. Simmer 5-l0 minutes. [time: 5-10 min] After all this there will be some black stuff. Let me tell ya that it is negligible coloration in comparison to the almost 90% converted mother lode of MD-P2Pol that lies in solution. So now there is this dark brown solution that has been cooled down to room temperature. MD-P2Pol is normally heavy enough to form its own oil layer. But like ephedrine, it has a water character bestowed to it by the OH. If a golden or brownish oil layer does not appear to separate from the water then, as Vogel says, the water can be saturated with table salt until oil appears. Sodium or potassium bisulfate has also been employed. The MD-P2Pol oil layer is merely separated or organic solvent extracted. If clean enough it can be used as is. However, distillation is always nice. Finally, like Vogel instructed his students, 'observe the odour'. Is there a tang of alcoholishness to it? Smells like victory! Now let's take a look at how that amusing, and admirably professional, home chemist named Zwit handled this particular conversion: Zwit makes MD-P2Pol from safrole (maybe): Just when you scurvy ridden freaks thought it was safe to surf A.D.C, ZWITTERION has returned, burned but not beaten! Actually, ZWIT is in PRETTY FUCKING GOOD SHAPE, especially after testing this new trick, courtesy of a mystery contributor in anon land. Thanks go to AN418658@anon.penet.fi for sending the experimental details on a process long suspected of being a viable way to produce the alcohol precursor to that ever-loved ketone, MDP-2-P. ZWIT ain't gonna go into any heavy-hitting theory crap here, but a quick OverView of what we's gonna do will be given. Alright, so you have some leftover Instant Power (tm) drain opener sitting around, and you're considering maybe tossing some on the local cat that always shits in your yard. WAIT! Before you make a nasty stinking mess, try making some MDP-2-Propanol! Yes! Yummmmm! Doesn't that sound TASTY?!?!?! Whaddya gonna do with that, you may ask in your blissful ignorance? Well hold onto your Depends (tm) undergarments, because you can do a LOT with it. For one thing, it's EASY to make alcohols from alkenes, this document will prove it, and for another, it's EASY to make alcohols into ketones! While some around here whine and moan about Markovnikov this and Markovnikov that (we won't name any names, but you know who you are), AN418658 delivers the GOODS. The pseudo-theory behind this process: Make the alkyl-hydrogen sulfate from the alkene using semi-concentrated, cooled sulfuric acid, then hydrolyse by heating in a near-boiling water bath. Here's what ZWIT did in a half-mole (based on amount of safrole) run... A 600mL beaker was situated in a ice/water bath on a mag stirrer and with a long stirrer bar (2") spinning happily away. 31g of distilled water was added and allowed to cool for 5 minutes, followed SLOWLY by 83g of concentrated sulfuric drain er... I mean, uh, acid. The acid heated the beaker up vigorously, so approximately 15 minutes were required to cool the contents back down. To what temperature? I dunno, it just felt cold to the touch (not the acid, idiot, the beaker). Next, 81g (.5mole) of distilled safrole (from sassafras oil) was added in a thin stream to the beaker. immediately, a light yellow color was apparent which slowly turned red, then brown (yuck - brown is never a good color in my book). This mixture was allowed to stir for 15 minutes. Next, a hot water bath was prepared, and the ritual bath salts thrown in for good measure and to keep the beaker Calgon smooth (it's a joke, you idiot). The beaker was transferred from the cold bath to the hot bath, and then 213mL of distilled water was added. In the scheme of things presented to me by the anon contributor, I should have dumped the 213mL of water into the beaker while still on the cold bath, then stirred for an additional 10 minutes, THEN placed on the hot water bath, but being a paragon of efficiency (or just plain half-assedness) ZWIT decided that the thermal inertia of the beaker contents would give the requisite 10 to 15 minutes of low-temp stir time and so skipped that tedium. Anyway, the beaker was allowed to stir in the hot water bath (heat provided by two beverage heater coils in a teflon-coated bread baking tin) for a total of 45 minutes, assuming that the contents were only actually at 90C or so for 30 minutes. The beaker was then removed from the heat and placed on a stirrer in free air to cool down until just warm. The contents are quite interesting looking, composed of a creme colored aqueous phase and a light-yellow organic phase (looks just like MDP-2-P, actually). Whoooooo-booooyyyeeeee, smells tasty, too. Hmmmm... well, it smells just like safrole, actually, with perhaps a hint of that alcohol quality to it. At any rate, now is when the solution must be neutralized with alkali. .15 molar equivalents of 5% sodium hydroxide is called for, which in this case works out to a total of 3g of anhydrous sodium hydroxide dissolved in the corresponding amount of water. ZWIT sucks at doing this sort of mindlessly-simple calculation, so 5g of NaOH (Red Devil Lye - nothing but the best for my drug precursors) was dissolved in 95g of water on the premise it wouldn't take that much to neutralize it??? Or are we really neutralizing it here? Who cares... 60mL of the solution was added to the beaker, delivering the required 3g of NaOH at the requisite dilution level of 5%. The pH meter said 170, which means the H+ ion concentration was still very high (or, in other words... what the fuck did I add the NaOH for?). ZWIT fairly expected this, but what the fuck, I'll just be a monkey on this one and follow directions. Now the slop is transferred to a sep funnel and allowed to sit. Even after 2 hours, it is apparent that this stuff is going to stay somewhat emulsified, and now ZWIT is shaking his old noggin' wondering why he even added the NaOH in the first place, as the stuff was clearly in two laters prior to that. Ugh... in fact, ZWIT surmises that it would probably be smartest to separate the alcohol from the aqueous acid layer THEN shake with base if necessary. Awww hell, it's not ZWIT's place to theorize, I leave that to the Brain Trust of A.D.C. Faced with the inexplicable, ZWIT dumps the sep funnel contents onto the ole vacuum buchner funnel and filters away. Lo and behold if that didn't straighten that nasty old emulsion mess up right straight! Funny, since that's what my anon friend TOLD me to do.. haha... well, such is life. ZWIT finally separates the two layers, properly, and extracts the aqueous side with 1x25mL of methylene chloride (yes, I chintzed out and only used *1* extraction). The organic only layer weighed in at 71g (without the extracts) so yield looks pretty good if the shit doesn't go to hell in distilling it. So of course it's time to distill, and distill ZWIT did! The extract was combined with the organic layer, dumped into a 24/40 ground glass simple distillation setup with vacuum receiver nipple, set stirring magnetically and heated with an electric Glas-Col (tm) heating mantle. The methylene chloride was stripped off, the last few drops flashed with vacuum, and the emulsified water stripped off under vacuum as well. The final reading on my manometer was 10mm Hg, and the temp climbed quickly to 120C where the MDP-2-Pol started coming over. The bp is supposed to be 113-116C at 3mm Hg, so I would expect the bp to be closer to 130 at 10mm Hg, but my thermometer adapter for my 24/40 stuff is notorious cantankerous and consistently reads about 8C too low. At any rate, it looked good! No, it looked FUCKING GREAT. The alcohol is fairly mobile, moreso than the ketone, and is nearly colorless but with the slightest tinge of perhaps lime green. The smell is not so pleasant as the ketone - very much like a heavy molecular weight alcohol with a tad of that isosafrole smell to it. Actually, it's hard to characterise the smell, as it doesn't have all that much scent to it. Anyway, the total yield of product, 3,4-methylenedioxyphenyl-2-propanol, was 72.0g, which comes out to a percent yield of 81%. Not bad for being intentionally sloppy, huh? Yes kids, I just converted plain old safrole to the secondary alcohol in under 4 hours total time with a percent yield of 81%, and I can only expect it to get better with more careful attention to detail next time and a more thorough extraction of the aqueous reaction matrix. Going from here to the ketone is a breeze, but at least one person (DrH) is a proponent of direct reductive amination starting from the alcohol. Hah! [END OF TRANSMISSION] Still not convinced that what Strike and ZWIT say is true? Well take a look at the following post by another chemist who had the same dream: Posted by sacredone on January 26, 1998 at 20:21:55: I beesy little bee had a dream one night after working feverishly in the lab. In this dream purifications and reactions were carried out that under normal, "awake state", circumstances would never be carried out. But in the hypothetical dream world the following was reported (quite lucidly as well): 1. Place 4 grams of 70% H2SO4 in test tube. Place 1.5 grams safrole in the other test tube. (Safrole is prepared by washing Brazillian Sass. with 5% NaOH (aq) followed by three water washes) ( H2SO4 is prepared from assuming that "ZEP" brand drain opener is 93% by weight and diluting to 70% by weight) 2. Place test tube rack in the freezer. Chill til ice cold (ice crstals should form around liquid lip of safrole in test tube). 3. Now, ice cold safrole was dumped into ice cold 70% H2SO4 and capped and vigourisly shaken 3 or 4 times. 4. Guess what? ONE FUCKING CLEAR LIGHT GREENISH/YELLOWISH phase! Safrole Hydrogen Sulfate has been formed. 5. While still cold, dump into 40 ml of water. A light cloudiness is observed immediately! What is reported as fine whitish particulates (oilets) are half suspended half solvated in the aqueous layer!!!!!! 6. 5 minutes of heating yields: The same damn off white oily suspension. Ever so slight discoloration but not much! There appears to be a little unreacted safrole, but not much. 7. Saturating this solution with salt (non-iodized) pushed the white oilet to the surface where they formed a nice happy oily/alcohol layer. 8. This was then carefully poured into a seperatory funnel (so as not to clog it up with the undissolved salt) and extracted with ether. The second and third extraction were performed on the solution but only after it had been made basic with 10% NaOH. This appeared to help the extraction. 9. The smell of the recovered alcohol was only very slight of safrole and is hard to describe due to the fact that it doesn't smell like much of anything! (Just like someone else we know reported!!!!!!). Approximate yield ~90%. Please remember, this is a micro, micro procedure, and appears (theoretically) to work thus far to obtain the alcohol. Upon more research, further dreams of a mad scientist will be posted!!!!!!! Without an FTIR, it would be difficult to 100% guaratee the validity of this procedure, but if indeed the alcohol can be obtained in this manner, so easily, and then oxidized by any various methods...oh BABY! ACID CATALYZED HYDRATION So what was that crap about acid catalyzed hydration we talked about in the Bromosafrole Page? Well, this here is it. Instead of worrying about inferior acid concentrations causing hydration (OH introduction) of our safrole, we want to encourage it! As you may or may not recall, we were yapping about the affinity water mlecules had for that beta carbon carbocation when we wanted so desperately to have Br plant itself there. We learned that the proton (aka the hydrogen) protonates the gamma carbon of safrole leaving the beta carbon ripe for an addition. Without sufficient concentration of acid a water molecule is dominant in this case and will slip in nicely to the beta position. Bummer for people looking to halogenate their safroles. Beauty for hydrationist. Let's exploit this, shall we. In the text "Organic Chemistry" [what else] by Carey (1st Ed., p. 216) we can read: "Another method by which alkenes may be converted to alcohols is through the addition of a molecule of water across the carbon-carbon double bond under condition of acid catalysis. Unlike the addition of concentrated sulfuric acid to form alkyl hydrogen sulfates, this reaction is carried out in a dilute acid medium. A 50% water-sulfuric acid solution is often used, yielding the alcohol directly without the necessity of a separate hydrolysis step. Markovnikov's Rule is followed: A proton adds to one carbon of the double bond and a hydroxyl group to the other." Water is itself weakly acidic. It has an H-something just like other acids. But it ain't strong enough to screw around with a double bond on its own. It needs help. The saprophtytic mother fucker needs acid. To do this reaction all one needs to do is to drip 50g of safrole or any allylbenzene into stirred flask or glass container containing 50g H2O and 50g H2SO4 (Close enough to 50%. Do the math.) The acid flask needs to be cooled below 10 deg C during the whole addition. After addition it's time to dilute the stuff with water and isolate the MD-P2Pol just like before. Worried that a little hydrogen sulphate may have been produced as before? Fuck it! Just heat the dilute stuff a few seconds. There's MD-P2Pol no matter what one does! Oh baby is this shit simple! Just playing around with different sulfuric acid concentrations has now produced MD-P2Pol two different ways! No one here is implying that these reactions are exclusive to H2SO4. One can use HCl, HBr, HI or any other strong protic acid. But H2SO4 is king. It is cheap. It is legal. The long-standing mark for how industrialized a nation is, is by how much H2SO4 that nation consumes. It is, literally, the stuff of industry. ACID CATALYSED DEHYDRATION Now that we got our alcohol let's just up and get rid of the damn thing. Gee, is that something we would really want to do? Well, for some people the answer is yes. Check it out. If we want to make an alcohol (a 'hydrate') we up the concentration of water. (a 50% H2SO4 - 50% H2O solution for example). Now, if we don't like the alcohol we can slap it around with yet another water/H2SO4 solution and a little heat and get right back to the same alkene we started with. Well, not exactly. If given a chance, any chance, things like safrole and allylbenze would love to switch out their double bond with the more energetically favorable one of isosafrole and propenyl benzene. This is their chance. When that OH of the isopropyl side chain goes by-bye, the resulting product is going to be a propenylbenzene. This is called an elimination reaction, by the way. Elimination reactions are the ones by which alkenes get formed. Now, don't get all excited yet. This dehydration process is going to involve both concentrated H2SO4 (70% or more) and heat. Not a recommended combination for safrolish molecules. But it will work well on speed's phenylisopropanol. That thing is a pretty sturdy molecule. Just in case you were wondering: No, this won't make a hydrogen sulfate like was done earlier. We are starting this time with an alcohol, not an alkene. In fact, there's so many things going on in this particular reaction that you really don't want to know what's happening. Just know that this is an easy little way to get a propenyl benzene. The following is a representative reaction taken from Vogel (p 230) with some stuff omitted and some things added: "Phenylpropene (Propenylbenzene) -- In a flask place 50g of water and then add 50% of conc. H2SO4. Allow this to cool below 10 deg. C using an ice bath, then add about 75g of phenylisopropanol (P2Pol)." Now (This is Strike talking here. What? Oh who the hell cares. Strike. Benny the Bee. Whatever), Vogel's target molecule in the reaction in his book is 2-pentanol. He wants to heat the reaction only to 40 deg C. His reason for doing so is that 2-pentene (the product he gets from the dehydration) will boil off at that temperature; so he sets up his system in a distillation arrangement so that the product will distill from the solution as it forms and be collected pure. That's all fine and dandy for a low boiling thing like 2-pentanol, but it won't work for P2Pol whose boiling point is much higher than the other reactants in the flask. But this shouldn't be a problem as you're going to find out in a second. What is particularly important right now is the temperature at which one could perform this dehydration. The lower the temperature the better. Right? Well, disregarding the boiling point of the 2-pentanol as a whole, the temperature of 40C should work. Apparently, a secondary OH (like the one on 2-pentanol) will pop off at 40C. That the species with a secondary OH happens to be P2Pol should make no difference. So fuck it! Just heat the P2Pol-H2SO4 solution to 40C for 30-60 min. (Strike is guessing at the reaction time here because: a) there's no corollary to time for this reaction and b) this happens to be a reaction that Strike has not done.) It seems reasonable to assume that higher temperatures would speed up the reaction and increase conversion. However, it will also increase protic destruction. Strike is also going to have to guess as to how the forming propenylbenze can or will be separated from the reaction. It seems to Strike that it may be quite possible that the P2Pol (or some of it) will initially dissolve into the aqueous acid solution owing to its OH character. So maybe the propenylbenze will, as it forms, drop out of solution to form its own oil layer. No matter what the solution ends up looking like, it can most assuredly be diluted with a ton of water to cause any formed propenyl benzene to separate out. From there it can be separated or extracted out. Any unreacted P2Pol should stay in the water layer. You know, 50% H2SO4 and 40C of heat really isn't that harsh come to think of it. It may very well work on MD-P2ol. There are things like rates of dissociation (or whatever) that can be calculated for the ether bonds of MD-P2Pol's methylenedioxy ring structure. It is possible that 50% H2SO4 and 40C of heat are, theoretically, a combination that those ether bonds could withstand. Stranger things have happened. Of course it may be that this reaction will only work if the product is able to leave the reaction as it forms like in Vogel's recipe. It may undergo unwanted additions or side reactions. Empirical observations of this reaction will appear in this page in the future. DEHYDRATION WITH KHSO4 Continuing our fun with the OH molecule we concentrate on a much less hostile way to get rid of it: KHSO4 catalyzed dehydration. KHSO4 (potassium bisulfate, not bisulfite) is sort of like sulfuric acid except that the H is a K. In "The Book" we talk about using salts like this to remove an OH group from the alpha carbon of MD-P-1-Pol as a way to get isosafrole: Chemists like to use KHSO4 on a molecule like MD-P1Pol because there is only one direction in which the double bond can form (the orbitals of the 1 carbon of the phenyl group are all full already). But we are fortunate in knowing that if applied to the OH of MD-P2Pol there really is only one double bond that is more energetically favorable to occur as well (Strike is just illustrating a point that if an OH were anywhere in the middle of a long chain hydrocarbon it would be eliminated to form an indiscriminate mixture of isomers). Whatever! Anyway, this little method is another quick and easy way in which one can use alcohol intermediates as a route to make either isosafrole or propenylbenzene. Oh man, is this simple! Put 60g of MD-P2Pol or 50g of P2Pol in a flask, then add 1g of KHSO4. Slowly heat the two together until 170C is reached. It is around this temperature that KHSO4 starts to have its way with the P2Pol's OH. One can physically see the results in the form of water vapor escaping the reaction mix as steam. Water is formed as the consequence of OH release. After 170C is reached the reaction is complete. Excess water is added and the isosafrole layer is separated for use as an ingredient for a potpouri bouquet.