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CuReUS
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a possible oversight by meth cooks ?
everyone who has read the hive,rhodium or vespiary files,knows that drug chemists are an ingenious lot.They come up with amazing reactions and
procedures.
but sometimes they can be quite stupid. Like this :
many must be familiar with the phenylacetone synthesis via phenylacetic acid and acetic anhydride.The anhydride is made by passing ketene through
acetic acid
instead of doing all that,why couldn't they just react ketene with benzylmagnesium chloride to get phenylacetone ?(I agree the yield of the anhydride
method is good,but still)
is it an abnormal reaction of benzyl grignards
I found an article on such abnormal reactions
so is the Mg method even possible ?
Attachment: austin1932.pdf (967kB)
This file has been downloaded 1139 times
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Loptr
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I dont know about the possibility, but how many people in general work with ketene?
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karlos³
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Possibly a lot less than people who use pyrrolysis with an acetate salt for phenylacetone production. They dont care about the bad yield, its a lot
less work, and they still get what they desire, so its enough for them.
Thats just my opinion, from knowing some people who are that desperate.
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Cou
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How is this not in detritus?
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Molecular Manipulations
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Because it's an interesting topic with actual uses and because you're not a moderator.
-The manipulator
We are all here on earth to help others; what on earth the others are here for I don't know. -W. H. Auden
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Bot0nist
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Well, this seems to me to be a thread discussing chemistry, and different novel routes to phenylacetone. Your of the opinion that it should be
detritus because its target product is a well known and very restricted precursor to an illicit drug? But Cou, I was under the impression that
discussion of procedures for CNS active compounds and their direct precursors is perfectly acceptable on this forum, so long as the discourse is
scientific, not "cookery or spoonfeeding," and is not motivated by obvious desire to get high or make profits. This thread is certainly discussing
clandestine drug chemistry and the ingenuity of its practitioners as they attempt to circumvent the obstacles of controlled and restricted reagents,
but it does not seem to be obviously nefarious in its goal, is not written in stupid "cook" lingo, and it appears that an attempt to understand and
discuss the chemistry involved was made so IMHO it seems within our guidelines.
While p2p most likely has no use in "legitimate" amateur chemistry, the ability to think outside the box in order to work around unavailable or
difficult and/or expensive reagents in order to achieve success is very much applicable to the amateur home chemists struggle.
*edit* What Molecular Manipulations said...
[Edited on 1-4-2015 by Bot0nist]
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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morganbw
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@CuReUS
Good question.
Now I wonder as well.
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Darkstar
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This idea was mentioned here in an old thread on Grignard reactions with acetic anhydride to give ketones. (see second post) Apparently benzylmagnesium chloride + ketene
would give poor yields. (one poster thought so, at least)
Also, according to the paper Rhodium posted, benzylmagnesium chloride + acetic anhydride gave phenylacetone in 52% yields. It might be worth
mentioning, however, that the reaction needs to be carried out at pretty low temperatures. (-70°C in the paper) To be honest, though, if you're going
to use benzylmagnesium chloride, unless the yields with ketene are actually somewhat decent, it seems like it'd just be easier to react it with dry
ice to get phenylacetic acid and then go the usual PAA + acetic anhydride route.
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CuReUS
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then I must say that you both have not been in touch with clandestine chemistry.In the old days,almost every cook had a ketene generator at home,and
the hive and DEA website are full of pictures of home made ketene generators.
there is also a story that once a cook was breaking bad when the DEA decided to give him a visit.He didn't want to rot in jail,so guess what he did,he
just stuffed the output tube of his K-gen down his throat.He was dead before the cops broke down the door
Quote: Originally posted by Darkstar  | This idea was mentioned here in an old thread on Grignard reactions with acetic anhydride to give ketones. (see second post) Apparently benzylmagnesium chloride + ketene
would give poor yields. (one poster thought so, at least)
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ha ha what can I say,I guess meth cooks aren't fools after all
in fact I got the idea while reading this journal
http://pubs.acs.org/doi/abs/10.1021/ed026p323
in that they react C2H5MgBr with ketene to get MEK
and the reference for the reaction is
(6) STAUDINGER, H., "DieKetene," Stuttgmt, 1912.
[Edited on 1-4-2015 by CuReUS]
Attachment: reactions of ketene.docx (173kB)
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Chemosynthesis
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At best, the jury is very much out on that first sentence. Just because someone said it doesn't make it correct, and the amount of errors made in idle
speculation of chemist wannabes on the internet is unquantifiable.
I'm also not sure where you get your information, but everything I have seen over the years points away from your claim that "in the old days almost
every cook had a ketene generator."
Acetic anhydride, phenylacetic acid, benzyl chloride and the like were not even not regulated until 1988 with the CDTA amendment to the Controlled
Substances Act, so the risk and unnecessary effort of using a ketene generator any earlier is effectively a non-argument.
http://www.dea.gov/resource-center/meth_lab_maps/2011.jpg
After that, pseudoephedrine and ephedrine based illicit syntheses became popular throughout the 90s, resulting in several Controlled Substances Act
amendments up through 2005, with a correlated shift in production towards Mexico, which some people have also connected NAFTA and cocaine
supply/demand to.
PMC2757051
Other than resourcefulness in reading household product ingredients lists (even less taxing while on stimulants, I imagine), I don't understand the
exultation of the clandestine "chemists" as a whole when they generally fail to perform even basic primary literary analysis of chemicals
characterized and synthesized numerous decades ago (often reaching 50-60 years ago now at least), and often seem to request an inordinate amount of
help in doing so. You are citing an article over a hundred years old now (1912?) and yet these people are "ingenious?" How so?
Other than slight alterations in procedure, I would say you are confusing "drug chemists" with the actual medicinal chemists who "come up with amazing
reactions" and usually did so long ago without the spoonfeeding requests I see coming from many of the nonprofessional/legitimate "drug types." Maybe
my background has made me a science snob, since the wannabes basically all get weeded out in a trial by fire, but the 'clandestine chemists'
almost universally fail to impress in any positive sense of the word.
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Bot0nist
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Perhaps I should have said resourcefulness rather than ingenuity, Chemosythesis, as I wasn't going for exultation. I'm quite sure that the run of the
mill meth cooks are not performing breakthrough, first of their kind procedures or eludicating reaction mechanisms very often. 
I was more trying to reference the type of flexibility and out of the box thinking that many home chemists (not just home drug chemists) often have to
employ to work around their limited resources and inability to source needed reagents. This does often seem to require digging up and reverting to
adaptations to much older techniques that were pioneered by truely ingenious and creative chemists with limited resources and no Sigma catalog.
All in I can't help but agree with your succinctly put post, as per usual.
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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Cou
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| Quote: Originally posted by Bot0nist | Perhaps I should have said resourcefulness rather than ingenuity, Chemosythesis, as I wasn't going for exultation. I'm quite sure that the run of the
mill meth cooks are not performing breakthrough, first of their kind procedures or eludicating reaction mechanisms very often.
I was more trying to reference the type of flexibility and out of the box thinking that many home chemists (not just home drug chemists) often have to
employ to work around their limited resources and inability to source needed reagents. This does often seem to require digging up and reverting to
adaptations to much older techniques that were pioneered by truely ingenious and creative chemists with limited resources and no Sigma catalog.
All in I can't help but agree with your succinctly put post, as per usual.
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I believe that the true fun/challenge in home chemistry is by preparing rare compounds with only chemicals available in stores. Common stuff like
bleach, or hardware store acetone. Suppose you want an uncommon compound such as methyl salicylate. You could just order it from Sigma, and now you
have it... but where's the fun in that? More fun to try making it from store-bought chemicals, as a challenge. Aspirin, acetone, methanol
[Edited on 1-4-2015 by Cou]
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clearly_not_atara
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Why on Earth would you use ketene for a reaction that proceeds on acetonitrile? Last time I checked only one of those compounds can
kill you by inhalation.
PhMeMgCl + MeCN >> P2P imine
Anyway it's not used because Grignards are too hard for meth cooks.
[Edited on 1-4-2015 by clearly_not_atara]
[Edited on 1-4-2015 by clearly_not_atara]
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morganbw
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| Quote: Originally posted by clearly_not_atara | Why on Earth would you use ketene for a reaction that proceeds on acetonitrile? Last time I checked only one of those compounds can
kill you by inhalation.
PhMeMgCl + MeCN >> P2P imine
Anyway it's not used because Grignards are too hard for meth cooks.
[Edited on 1-4-2015 by clearly_not_atara]
[Edited on 1-4-2015 by clearly_not_atara] |
I agree mostly, ( >95% of the meth cooks )
But I promise you there are meth cooks who are also chemist. I doubt they would use Grignards but the ability is out there.
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Molecular Manipulations
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Meth cooks mostly just follow a "recipe" and don't care what reactions are going on. Sure there's certainly a few who were first chemists and realized
the profit they could make, and decided to cook meth, and others probably cooked meth first and then decided they liked chemistry and chose to learn
more. However this is the minority, most just want some bank and decide cooking is for them.
Benzylmagnesium chloride isn't that easy to get, and they want as little steps as possible.
-The manipulator
We are all here on earth to help others; what on earth the others are here for I don't know. -W. H. Auden
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morganbw
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| Quote: Originally posted by Molecular Manipulations | Meth cooks mostly just follow a "recipe" and don't care what reactions are going on. Sure there's certainly a few who were first chemists and realized
the profit they could make, and decided to cook meth, and others probably cooked meth first and then decided they liked chemistry and chose to learn
more. However this is the minority, most just want some bank and decide cooking is for them.
Benzylmagnesium chloride isn't that easy to get, and they want as little steps as possible. |
Agree in total.
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CuReUS
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| Quote: Originally posted by clearly_not_atara | Why on Earth would you use ketene for a reaction that proceeds on acetonitrile? Last time I checked only one of those compounds can
kill you by inhalation.
PhMeMgCl + MeCN >> P2P imine
|
and pray tell me dear ,from where you you are going to get acetonitrile.AFAIK,humans don't shit it out.
and even if you got the nitrile and made the imine,you would have to use a non aqueous reduction method(although I have never heard of reducing a grig
intermediate),like hydride or H2/catalyst,or your precious imine will get frapped
it isn't that hard either
like BOtanist,I praised the cooks for their ingenuity,I didn't say they were geniuses.And what I meant by saying that they came up with "amazing
reactions" was their effort to search for reactions from literature,in a "pre" internet era.Imagine sitting in the library the whole day,with no
google to help you and no pdfs to save.It was a tough time indeed and for that they should be praised.Also many didn't know shit about chemistry when
they started,but they went on to become decent cooks.They were not taught in Ivy league colleges,with state of the art facilities by nobel
laureates.They learnt what they could and they applied it .
[Edited on 2-4-2015 by CuReUS]
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karlos³
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In a pre-internet era you could just buy the phenylacetone .
At least in europe.
Piperonylacetone too.
Methylamine, also no problem, not just then, still no problem to buy.
As for ingenuity, the reaction from bought phenylacetone and methylamine is even described in the organikum.
Just one book to pick, not hours or even days in the library, most pharmaceutic chemistry books also have this "recipe".
| Quote: | : Originally posted by clearly_not_atara
Why on Earth would you use ketene for a reaction that proceeds on acetonitrile? Last time I checked only one of those compounds can kill you by
inhalation.
PhMeMgCl + MeCN >> P2P imine
and pray tell me dear ,from where you you are going to get acetonitrile.AFAIK,humans don't shit it out.
and even if you got the nitrile and made the imine,you would have to use a non aqueous reduction method(although I have never heard of reducing a grig
intermediate),like hydride or H2/catalyst,or your precious imine will get frapped |
Just skip the hydrolysis, transfer the imine to an anhydrous methanolic NaBH4 solution?
Its not that complicated.
Also, just buy the acetonitrile, its cheap and an ordinary solvent.
[Edited on 2-4-2015 by karlos³]
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Chemosynthesis
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I definitely agree with Bot0nist and Cou that being limited in reagent selection can be intellectually stimulating,
and solving such a problem is rewarding in itself. I wish it weren't necessary for hobby chemistry, but at least one should try and enjoy what they
cannot change.
I knew some undergrads and even a few med/grad school students who at least openly considered supplementing their tutoring money/stipends with illicit
synthesis. It wasn't really a common discussion, and I think only a couple probably followed through (one getting caught misappropriating research
equipment by their PI during work hours). I have read some trial excerpts where prosecution claimed professional chemists synthesizing illicit
chemicals for profit was thought to be rare, and I believe this to be the case for a number of reasons.
Yet I have seen self-avowed "meth cooks" act as though a Grignard were a 'holy grail' rite of passage for organic chemists, while arguing against
people who seemed educated in the subject. Any sophomore level first year organic chemistry student at a community college should have performed a
Grignard as part of their academic work. It doesn't take an Ivy League Nobel Laureate trained chemist, and you are quite correct in a Grignard
reaction not being all that difficult.
| Quote: | like BOtanist,I praised the cooks for their ingenuity,I didn't say they were geniuses.And what I meant by saying that they came up with "amazing
reactions" was their effort to search for reactions from literature,in a "pre" internet era.Imagine sitting in the library the whole day,with no
google to help you and no pdfs to save.It was a tough time indeed and for that they should be praised.Also many didn't know shit about chemistry when
they started,but they went on to become decent cooks.They were not taught in Ivy league colleges,with state of the art facilities by nobel
laureates.They learnt what they could and they applied it .
|
Back in those times, despite a lack of internet access, there were still card catalogs, inter-library
loans, and printed ACS archives (that exist today). Literary research was more time consuming, but everyone did it... not just the chemical literati.
Ask any Baby Boomer if they visited the library in high school, and they should tell you that they were quite capable of using these systems. Should
they be praised too?
The history of most outlaw motorcycle groups, the ones history seems to suggest ruled the meth trade in the 60s on through the 90s, is one of
returning veterans. There are rumors perpetuated in outlaw motorcycle circles that the GI bill allowed gang members to attend college enough to learn
how to "cook" meth. This makes sense. The knowledge was then passed on in an apprenticeship fashion.
I can't cite this, but you can ask someone in relevant law enforcement and see if they tell you the same thing I've been told. You see this today
where most "cooks" caught by law enforcement in rural America, if you ask them, are supposed to smurf for themselves and maybe a couple other people.
They often claim to learn the same way. I find this a very different standard from someone who actually learned some chemistry, illicit drug producer
or not, which I believe to be pretty rare. People interested in chemistry learn chemistry. They may have additional interest in money, drugs, or
whatever... but people solely interested in the above probably don't want to bother really learning chemistry any more than as a means to an end.
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CuReUS
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| Quote: Originally posted by karlos³ | In a pre-internet era you could just buy the phenylacetone .
At least in europe.
Piperonylacetone too.
Methylamine, also no problem, not just then, still no problem to buy. |
karlos,please U2U me where you live,I might retire there
| Quote: | As for ingenuity, the reaction from bought phenylacetone and methylamine is even described in the organikum.
Just one book to pick, not hours or even days in the library, most pharmaceutic chemistry books also have this "recipe". |
reductive amination was the reaction that kick started the trade,just like the first telephone or car.There were many more developments that can't be
found so easily
ex-have you heard of lithium triethyl borohydride or reactions using tetra nitro methane.
| Quote: | Just skip the hydrolysis, transfer the imine to an anhydrous methanolic NaBH4 solution?
Its not that complicated. |
maybe that's why NaBH4 is a watched chemical
| Quote: | | Also, just buy the acetonitrile, its cheap and an ordinary solvent. |
it is not "cheap" everywhere
by the way,did anyone manage to get the german reference on ketene .Let's stick to the chemistry.
I found something interesting
| Quote: | Phenylmagnesiuni Bromide and (A). First Experiment.
-Twenty-five cc. of absolute ether (distilled from a
Grignard preparation) and 8.5 g. (0.06 mole) of the ketene
were mixed. Then 0.06 mole of phenylmagnesium bro-
mide was dropped into it. Following the vigorous
reaction, the soluticin was refluxed for one-half hour, then
stirred with dilute sulfuric acid. The ether layer was re-
moved, washed with dilute sodium carbonate and dried
over calcium chloride and distilled. Vacuum distillation
(11 mm.) of the residue gave these fractions: (1) 70-120°,
3 g.; (2) 120-170°, 7 g. Redistillation of the 3 g. fraction
revealed no constant-boiling material. It distilled be-
tween 90-120' (11 mm.). The 7-g. fraction was chiefly
ethyl a-benzoylbutyrate.'* Si grams of it was collected
at 159-162" (11 mm.). Its Identity was established as
follows: (1) its saponification number was 215 (calcd.
210); (2) it was refluxed for 2.5 hours with a 5% solution
of potassium hydroxide, then ether extracted, the extract
dried and the ether removed. The 2 g. of residue con-
tained some diphenyl but it was largely phenyl n-propyl
ketone. It gave a semicarbazone, m. p. 184-185" |
so ketene with phenyl grig will give a beta keto ester and not a ketone directly.the B-keto has to be hydrolysed to get the ketone
http://pubs.acs.org/doi/abs/10.1021/ja01314a005
[Edited on 3-4-2015 by CuReUS]
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cal
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| Quote: Originally posted by morganbw | | Quote: Originally posted by Molecular Manipulations | Meth cooks mostly just follow a "recipe" and don't care what reactions are going on. Sure there's certainly a few who were first chemists and realized
the profit they could make, and decided to cook meth, and others probably cooked meth first and then decided they liked chemistry and chose to learn
more. However this is the minority, most just want some bank and decide cooking is for them.
Benzylmagnesium chloride isn't that easy to get, and they want as little steps as possible. |
Agree in total. |
There are two types of meth manufactures, 1. Cooks whom have been shown a recipe and follow it because that is what they know. 2. A knowledgable
person in chemistry who can pick and choose from available starting chemicals .
There are about 13 different methods to produce p2p from over the counter chemicals in natural state or that can be removed easly from a combination
of other chemicals. Ketene was just a simple device and yield was not a deciding reason, because the street value was about $ 10,000.00 a pound, so
even a 32% yeild gave a return many times greater than the investment.
Thought is an action, which when acted upon becomes work and sometimes art!
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byko3y
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Ketene lamp is not just another device, it's just another way to perform suicide. One breath of it can easily be lethal. Along with cyanides, phosgen
generators, thionyl chloride, phosphoryl chloride, phosphine, hydrogen sulfide and many other fun chemicals.
LC50 for acetic anhydride is 1,000 ppm/4h, while LC50 for ketene is 300ppm/1min (0.08ppm/1h), just 10 000 times lower. This one should be used only in
a well ventilated hood with a gas filter, because without the filter a leakage will kill someone else.
Totaly agree that phenylacetic acid + acetic acid is the easiest and safest way with a good yield of P2P. And AFAIK phenylethanol is not controlled in
any way, so you can just go straight via hypochlorite. And even if the phenylethanol is banned - you can use styrene to get either phenylethanol via
something like anti-Markovnikov halobromination or Willgerodt-Kindler, so why the hell anyone would even think about handing ketene?
Odor threshold for ketene is about 12 ppm, so you need 30 minutes to become completely dead without noticing the odor.
[Edited on 20-4-2015 by byko3y]
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karlos³
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I would say the easiest and safest way is to reduce 1-phenyl-2-nitropropene, also very great yielding?
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byko3y
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Yes, I'm just wondering why it is not on the DEA precursors list... but who does sell it? I can't seem to find any major chemical provider who sells
P2NP, while you can get a relatively cheap nitroethane after filling end user declaration
And nitroethane synthesis is a pain in the ass, while you can reach the P2P in 3 steps using 100% OTC chemicals. So basically we end up in the 1995
when you could just purcahse the goddamn P2P.
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CuReUS
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how ? I thought hypochlorite was only strong enough to oxidise it to aldehyde. | Quote: | | you can use styrene to get either phenylethanol via something like anti-Markovnikov halobromination |
even if you do anti marko using peroxide and HBr ,in the hydrolysis step,the carbocation will again form at the benzylic position.You could do
hydroboration oxidation though.wonder from where you would get borane
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