Allylbenzenes

What happens when isomerization is performed is that the double bond of the allylbenzene safrole migrates to the more energetically favorable position between the alpha and beta carbons of the propyl side chain. Thus isosafrole, a propenylbenzene, is born. 

Gee, that all sounds fine and dandy. But Strike saved the best for last. Without a doubt, the cleanest, fastest and easiest method for isomerizing safrole and other allylbenzenes is to use CaOH. Someone who is Not Tim (Strike s name for her) emailed Strike the Chemical Abstracts entry for the procedure ... 

Strike can t believe Strike can actually quote Strike s own book. That is so freaky )]. Most of these things will make amphetamines that are much more potent than X. It is also possible to play around with some of the little side groups on these to eventually make X or some other interesting psychotomimetics. With few exceptions these precursors are all substituted allylbenzenes just like safrole. They are all found in the same kind of legal oils and sold in the same kinds of places as sassafras. Finally, these precursors are turned into their own respective amphetamines using the exact same conversion recipes used for safrole. 

The standard way that scientists get these allylbenzenes and other goodies out of these oils is by careful, fractional distillation. You can see from above that some of the more desirable allylbenzenes do not occur in high concentrations in the oils they are found in. So that means there is a lot of crap one has to get rid of to isolate the goods. This is not as big of a concern as one might think. 

People with or without distillation apparatuses can take advantage of this fact. Just boil or distill off most of the oil up to the temperature of your preferred allylbenzene and stop. There is a very good chance that what is left will be a majority of what is wanted. 

The literature states that if one uses ice cold, concentrated sulfuric acid on a terminal alkene (a.k.a. allylbenzene) an alcohol (OH) intermediate will form Markovnikoviy on the secondary carbon (don t ask). What does this mean Let s take an example. Say one has some elemi oil and wants that elemicin that is in it. What one can do is chili, say, 500mLs of the oil to freezing and do the same for about 100-200mLs of concentrated sulfuric acid (at least 90% cone.). Next, one just mixes the two together for about 5 min. What will happen is that the cold H2SO4 will make a hydrogen... 

Hey That really wasn t a lot of work. Just a lot of talk on Strike s part. All one did was mix an oil with some acid, added water and isolated. One gets some pure propenylbenzene without distillation. Done on a massive scale, this is a cheap method for getting lots of small concentration allylbenzene compounds out of complex oil mixes. And since Strike blew so much dough on this glorified extraction protocol, someone better damn well use it (In an academic lab of course). 

METHOD 2 Without a doubt, this is the current world favorite for making P2Ps. This method is known as the Wacker oxidation and involves mixing safrole (or any other allylbenzene), palladium chloride, cuprous chloride and dimethylformamide in an oxygen atmosphere to get MD-P2P very quickly and in a totally clean manner [11, 12]. There s also a very nice review in ref. 13. 

The last variation we should discuss is about the use of solvent. Ever-bitching about the rarity and price of chemicals, the bees have thrust their anger at the DMF used in this method. TDK sent Strike an article that gives some credence to this [16]. In it the alcohols methanol, ethanol, 1-propanol, ethanediol and others were used in place of DMF with beautifully high yields. Below is the sample experimental from the article Oust picture using safrole or allylbenzene in place of the 1-hexene) ... 

For the past year Strike had been in consultation with contract labs over the making of phenylisopropyl alcohols using sulfuric acid and allylbenzenes (don t ask). The lab owners would listen patiently as Strike primitively described how and why an OH should go on the beta carbon. And without exception, the lab owners would point out to Strike that the best way to get an OH on the beta carbon would be to put a Br there first. But Strike don t wanna put a Br there first Strike would say, Strike wants the OH put on directly using sulfuric acid " The lab guys had to do what Strike said because Strike was holding all the money (...a fool and her money etc.). But out of curiosity Strike asked how they would get that Br on the beta carbon. Every one of them said it was simply a matter of using the 48% HBr in acetic acid. They even showed Strike their stock solutions (usually from Aldrich or Fisher). 

For molecules similar to safrole or allylbenzene we take the work done on any terminal alkene such as 1-heptene, 1 octene. Another term to look for is olefin which is a term for a doublebond containing species. What we then look for are articles about these olefins where the functional groups we are looking for are formed. Articles with terminology like methyl ketones from (P2P), ketones from , amines from etc. Or when we want to see about new ways to aminate a ketone (make final product from P2P) we look for any article about ketones where amines are formed. Sound like science fiction to you Well, how do you think we came up with half the recipes in this book It works ... 

To do the reaction the chemist places a flask in an ice bath on top of the stirplate and into it is added lOOmL acetonitrile (CH3CN) and 65g anhydrous mercuric nitrate. A small separatory funnel that has 33g of safrole or 24g allylbenzene is placed over the flask so that everything looks just like that of fig. 9. The safrole is then slowly dripped in so that the temperature stays between 20-28 C. A yellow precipitate will form as the mercuric nitrate latches on to the safrole. After the addition is finished, the ice bath is removed and the solution stirred at room temperature for 1 hour. 

The acetonitrile and mercuric nitrate amounts remain the same except they are to be accompanied by 12.6g of fuming nitric acid (see chemicals section) in the reaction flask. Then, with cooling, the safrole or allylbenzene is added just like before. The reaction is immediate and takes no more than 20 minutes of stirring after which lOOmL ice cold dH20 is slowly added. Next, with vigorous stirring, saturated sodium chloride solution is slowly added until a pronounced precipitate forms. This yellowish mass is the chloride. 

This method was designed to produce an acetyl intermediate just like that in the failed recipe a few paragraphs above using only sulfuric acid and acetonitrile [93]. This reaction works, in theory, in a so-so manner on allylbenzene but not on safrole. This method will not make X for many reasons. So why does underground literature and DEA forensic scientists keep claiming that it does Strike doesn t know either. Let s see what the man who invented this. Dr. Ritter, had to say back in 1952 "several attempts to obtain amides from...safrol (sic) were fruitless. [94]. What makes all these people think that this will work unless no one did their homework. This is another sore spot of Strike s and... 

This is the infamous Friedel-Crafts method and works in a manner similar to the previously mentioned method where P2P was made by merging benzene and chloroacetone using AICI3. This method is for speed makers only and is not recommended for conversion of 1,3-benzodioxole. However, this should work in a limited way on catechol. The conversion factor is very low but that isn t a major concern of speed chemists because cheap old benzene is the precursor and all of that benzene that isn t converted can be run back through this simple little process over and over again. Before she knows it, the chemist will have amassed an enormous amount of allylbenzene [139, 140]. 

There is one other benzene to allylbenzene method that you should take a look at. Osmium sent in the article in which that magical clay and other similar catalyst add the allyl to aryl in record fashion. To read more check out ref 143. 

Less reactive electrophilic reagents like those involved in acylation or alkylation apparently do not react with phenyl-substituted pyrylium salts the p-acylation of a phenyl group in position 3 of the pyrylium salt obtained on diacylation of allylbenzene (Section II, I), 3, a), and the p-l-butylation of phenyl groups in y-positions of pyrylium salts prepared by dehydrogenation of 1,5-diones by means of butyl cations (Section II, B, 2, f) probably occur in stages preceding the pyrylium ring closure. 

An alternative approach to phosphine-free ruthenium precatalysts is based on pyridine complex 70 [48], which has been established by Grubbs et al. as a valuable precursor for other mixed NHC-phosphine complexes (cf. Scheme 15). Complex 70 is only moderately active in the cross metathesis of allylbenzene... 

This mechanism is exactly analogous to the allylic rearrangement mechanism for nucleophilic substitution (p. 421). The UV spectra of allylbenzene and 1-propenylbenzene in solutions containing NH2 are identical, which shows that the same carbanion is present in both cases, as required by this mechanism. The acid BH protonates the position that will give the more stable product, though the ratio of the two possible products can vary with the identity of BH". It has been shown that base-catalyzed double-bond shifts are partially intramolecular, at least in some cases. The intramolecularity has been ascribed to a conducted tour mechanism (p. 766) in which the base leads the proton from one carbanionic site to the other ... 

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