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Author: Subject: Phenylacetones from vicinal dihalides
cannizzaro
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[*] posted on 16-7-2008 at 08:40
Phenylacetones from vicinal dihalides


Hi!
I'm very intrestingly, who is tried to make it?
Someone has articles about it? Thanks for the help.

Method of making phenylacetone derivatives

Example 1

75 g. of 15% potassium hydroxide is added to 23.3 g. 1-(3,4-methylenedioxyphenyl)-1,2-dichloropropane and agitated 10 hours, cooled to room temperature, extracted twice with 200 ml benzene, dried and evaporated (with heat) to get 15.2 g. 3,4-methylenedioxyphenylacetone(yield 85.4 %). The boiling point is 149-151º C/10mm Hg.

Example 2

80 g. 20 % sodium hydroxide is added to 33.8 g. 1-(3,4-dimethoxyphenyl)-1,2-dibromopropane (melting point 90-93º C.) and boiled for 12 hours. After steam distillation and extraction with benzene 18.4 g. of a light yellow color oil is obtained. It is pure 3,4-dimethoxyphenylacetone (yield 95.0 %). The boiling point is 133-137º C/10mm Hg.

[Èçìåíåíî 16-7-2008 ... cannizzaro]
<sub>Edit by Nicodem: Changed the "P2P" acronym from the title.</sub>

[Edited on 17/7/2008 by Nicodem]
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Filemon
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[*] posted on 16-7-2008 at 13:18


..and how do you make the 1-(3,4-methylenedioxyphenyl)-1,2-dichloropropane? It will be [...]2,2-dichoropropane
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cannizzaro
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[*] posted on 16-7-2008 at 13:41


Very simply,
C6H5CHO---C2H5MgBr--->C6H5CH(OH)CH2CH3---KHSO4--
-->C6H5CH=CHCH3---Br2--->C6H5CHBrCHBrCH3---NaOH--->P2P or phenylacetone derivatives, but I cannot find a technique of last transformation, help me if you know
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Filemon
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[*] posted on 16-7-2008 at 15:30


It doesn't work this way:

C6H5CHBrCHBrCH3---NaOH---> C6H5CCCH3 => C6H5CCCH3 + H2O + Hg2+ + H+ => C6H5COCHCH3 and C6H5CH2COCH3
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cannizzaro
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[*] posted on 16-7-2008 at 16:36


ok, thanks for advice, but it has been written in the patent
and here https://www.hyperlab.info/inv/index.php?act=ST&f=17&... [post=500388]

now I want to found articles about transformation:

C6H5CH=CHCH3---1)H2O2,HCOOH;2)[H+]--->P2P

Someone has articles about this transformation?

[Èçìåíåíî 17-7-2008 ... cannizzaro]

[Èçìåíåíî 17-7-2008 ... cannizzaro]

[Èçìåíåíî 17-7-2008 ... cannizzaro]

[Èçìåíåíî 17-7-2008 ... cannizzaro]
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[*] posted on 16-7-2008 at 16:48


Making phenylacetone or its analogues outside an experimental lab is an offence in most places.

Get a job, find yourself a friend, have a nice life, maybe have a few children together.
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[*] posted on 16-7-2008 at 17:58


Quote:
Originally posted by ScienceSquirrel

Get a job, find yourself a friend, have a nice life, maybe have a few children together.


Perhaps that is the plan and all the phenylacetone pondering are just related to working out the route.




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[*] posted on 16-7-2008 at 18:39


Quote:
Originally posted by Filemon
It doesn't work this way:

C6H5CHBrCHBrCH3---NaOH---> C6H5CCCH3 => C6H5CCCH3 + H2O + Hg2+ + H+ => C6H5COCHCH3 and C6H5CH2COCH3


C6H5CCCH3 + NaNH2 =(heat)=> C6H5CH2CCNa + NH3 (g)
or
C6H5CCCH3 + NaOH =(heat, triglyme+toluene)=> C6H5CH2CCNa + H2O (azeotroped off with tol,)

The base catalysis isomerisation between the terminal and internal alkyne, the terminal alkyne gets 'pinned' by forming the sodium salt.

C6H5CH2CCNa + H2O =(cold) => C6H5CH2CCH + NaOH

C6H5CH2CCH + H2O =( Hg(2+) & H(+) )=> C6H5CH2COCH3

Quote:
now I want to found articles about transformation:

C6H5CH=CHCH3---1)H2O2,HCOOH;2)[H+]--->P2P


You'll most likely find more generic or using other alkenes for the diol formation ( http://www.orgsynth.org/orgsyn/pdfs/CV3P0217.pdf ) and the pinacol rearrangement. There is some written on the specific rearrangement, because of the mechanism for this case.

[Edited on 17-7-2008 by not_important]
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[*] posted on 16-7-2008 at 21:50


Isomerization? With a methyl?! That's not something they told me about. How does that happen? Inductive effect can't possibly be enough, not with mere NH2- or OH- around.

Tim




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[*] posted on 16-7-2008 at 22:20


Diene intermediate. See http://classes.yale.edu/02-03/chem125a/125webSpring/Isomeriz...

and specifically newer methods (I learned of the reaction in an org chem book published in the 1930s)

http://article.pubs.nrc-cnrc.gc.ca/ppv/RPViewDoc?issn=1480-3...

http://article.pubs.nrc-cnrc.gc.ca/ppv/RPViewDoc?issn=1480-3...
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[*] posted on 16-7-2008 at 22:56


Well, actually it goes trough the allene stage (the term diene is more or less used only for two conjugated double bonds) and the isomerization is driven by the deprotonation trough the enormous difference in pKa's between propargylic C-H and acetylenic C-H (~17 magnitudes of difference).

Regarding the original question of the thread... There is not much else in the literature about Ar-CHX-CHX-Me => Ar-CH2-CO-Me besides the JP patent already cited (at least nothing that I could find in few minutes of search). Also, all the reaction mechanisms I could imagine don't look something that would like to happen on such systems. In short, I would be skeptical about that patent until additional information.

Quote:
Originally posted by ScienceSquirrel
Making phenylacetone or its analogues outside an experimental lab is an offence in most places.

Get a job, find yourself a friend, have a nice life, maybe have a few children together.

I can agree with the advice bellow but the your claim about making of phenylacetone "analogues" being a legal offense is simply not true. Preparing phenylacetone is not a crime in most of the world and neither is preparing its ring substituted versions or whatever analogue (= similar compounds, which is a term so vague as to mean nothing). However, here I do not like to see any recipe oriented discussions on the synthesis of phenylacetone itself, most particularly if the original poster uses acronyms like "P2P" or any acronym of criminal background. So, to all those replying, please stick to the chemistry. If the discussion diverges out of the chemical discourse too much, then you all know where this thread will end.




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cannizzaro
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[*] posted on 16-7-2008 at 23:06


Quote:
Îðèãèíàëüíîå ñîîáùåíèå îò ScienceSquirrel
Making phenylacetone or its analogues outside an experimental lab is an offence in most places.

Get a job, find yourself a friend, have a nice life, maybe have a few children together.


maybe you are right...
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[*] posted on 16-7-2008 at 23:34


Quote:
Originally posted by Nicodem
Well, actually it goes trough the allene stage (the term diene is more or less used only for two conjugated double bonds) ...


Yeah, you're right. Never type tech stuff while cooking, the mind is elsewhere.
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[*] posted on 17-7-2008 at 02:16


Quote:
Originally posted by not_important
Diene intermediate. See http://classes.yale.edu/02-03/chem125a/125webSpring/Isomeriz...


Ah, fascinating. So between OH- and NH2-, one could interconvert terminal vs. internal alkyne? Or wait, the water step was uber slow, or is heat enough to make that move? Oh well, I'm going to bed anyway :D

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[*] posted on 17-7-2008 at 05:03


OK, I typed too hastily but some people who are intending to make 3,4-methylenedioxyphenylacetone will be ending up in the local chokey when they carry out their next step.

[Edited on 17-7-2008 by ScienceSquirrel]
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[*] posted on 17-7-2008 at 08:01


Quote:
Originally posted by 12AX7

Ah, fascinating. So between OH- and NH2-, one could interconvert terminal vs. internal alkyne? Or wait, the water step was uber slow, or is heat enough to make that move?


Yup - takes heating over solid KOH to happen fast enough to be useful. If there several isomeric internal alkynes you usually get a mixture, and side reactions occur with both OH and amines.

The diamines used in the newer reports work better for getting the terminal alkyne than plain old -NH2; and you need an excess of the amide so as to lock the terminal alkyne. With KOH and the shift to internal you can use lesser amounts of the base.
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[*] posted on 18-7-2008 at 10:11


Quote:
Originally posted by cannizzaro
ok, thanks for advice, but it has been written in the patent
and here https://www.hyperlab.info/inv/index.php?act=ST&f=17&... [post=500388]

now I want to found articles about transformation:

C6H5CH=CHCH3---1)H2O2,HCOOH;2)[H+]--->P2P

Someone has articles about this transformation?

[Èçìåíåíî 17-7-2008 ... cannizzaro]

[Èçìåíåíî 17-7-2008 ... cannizzaro]

[Èçìåíåíî 17-7-2008 ... cannizzaro]

[Èçìåíåíî 17-7-2008 ... cannizzaro]


It doesn't work this way.

C6H5CH=CHCH3---1)H2O2,HCOOH;2)[H+] => C6H5CHOHCHOHCH3 + KHSO4 = > P2P

The alcohol bencilic position is more reactive, it dehydrated before.

CH=CHOH => CH2-CO
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