| Pages:
1
2 |
Douchermann
Hazard to Others
Posts: 117
Registered: 11-10-2005
Location: Illinois, USA
Member Is Offline
Mood: No Mood
|
|
methylenedioxybenzyl chloride + sommelet?
In this link:
http://www.erowid.org/archive/rhodium/chemistry/piperonal.ni...
a method is given to produce piperonal from methylenedioxy benzene, with the substituted benzyl chloride being an intermediate. My question is, can
the sommelet reaction work to produce an aldehyde from this? Why or why not? (I'm more interested in the theory than practicality)
Thanks
It\'s better to be pissed off than to be pissed on.
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
I don't see why not.
If you search on 'piperonal sommelet' you will find that several patents refer to the preparation of this compound by this method.
|
|
|
Douchermann
Hazard to Others
Posts: 117
Registered: 11-10-2005
Location: Illinois, USA
Member Is Offline
Mood: No Mood
|
|
Haha whoops, forgot to search other places than just sciencemadness. Well thank you.
It\'s better to be pissed off than to be pissed on.
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Refluxing in somewhat conc. HCl might damage the methylendioxy bridge though... So better use more dilute acid and lower temps.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
smuv
National Hazard
Posts: 842
Registered: 2-5-2007
Member Is Offline
Mood: Jingoistic
|
|
GB1538214: What is refrenced in the rhodium article (its always best to track down the primary source)
Journal of Asian Natural Products Research, Vol. 9, No. 1, January–February 2007, 23–28.
Similar procedure; 82% yield on a 50mmol scale.
[Edited on 9-25-2008 by smuv]
"Titanium tetrachloride…You sly temptress." --Walter Bishop
|
|
|
Douchermann
Hazard to Others
Posts: 117
Registered: 11-10-2005
Location: Illinois, USA
Member Is Offline
Mood: No Mood
|
|
Excellent, thank you all.
Klute: In the sommelets I have performed, the HCl is quite dilute in the final mixture, not to mention the concentration would decrease rapidly due to
the formation of the methylamine hydrochloride
It\'s better to be pissed off than to be pissed on.
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Good point.
The yields of piperonyl chloride from chloromethylations are very impressive. PainKilla had it right all along 
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
The Kornblum oxidation using NaHCO3/DMSO at 100°C works very well on benzyl chlorides. You might consider this as an alternative depending on the
substrate nature. The Sommelet reaction is fine but it suffers from poor yield on ortho-substituted benzyl chlorides while the Kornblum oxidation does
not have this limitation.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Has anyone have the mp for piperonyl chloride and bromide? I don't have a handbook, and quite surprisingly haven't found anything (bo or mp) by
searching the net.
I suppose both are solids?
BTW, I'm considering using them to prepare Cassione, or 4-(3',4'-methylendioxyphenyl)butan-2-one, a derivative of Raspberry ketone that smells like
blackcurrant, by alkylating acetoacetate anion. Less trouble than going through the aldehdye IMHO.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
smuv
National Hazard
Posts: 842
Registered: 2-5-2007
Member Is Offline
Mood: Jingoistic
|
|
I ran a quick beilstein search...
For the bromide: mp range 45-50 the average being about 48c
Bp: 101-103c @ .1 torr; 110c @ 5 torr
For the chloride: mp range 20-23; most being 23
Bp: 78-80C @ .05torr; 89-91 @ 1torr; 134-135 @15 torr
I have not checked primary literature so keep that in mind; these are just straight from a database.
EDIT: Just to clarify the MP range is the min and max melting point recorded in the literature search among all the data collected.
[Edited on 9-30-2008 by smuv]
"Titanium tetrachloride…You sly temptress." --Walter Bishop
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Thank you very much Smuv. I guess the bromide is more practical to work with (recrystallization), less volatil and (possibly?) irratating?
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
smuv
National Hazard
Posts: 842
Registered: 2-5-2007
Member Is Offline
Mood: Jingoistic
|
|
The conditions required to make the bromide might compromise the dioxol ring. Maybe look into it. After all HBr used to be used to cleave phenol
ethers (albeit under harsher conditions).
If it were me...I would make the chloride; even if I could never practically recrystallize it. After distillation I am sure it would be pure enough
to move onto the next step (all the side products I can fathom would have much higher bp's and also could be readily detected by TLC).
Whichever route you choose, good luck.
"Titanium tetrachloride…You sly temptress." --Walter Bishop
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
I have stumble don several prearation forming the bromide form the alcohol with aq. HBr at RT or under in good yields:
WO 98/22417:
and J. CHEM. SOC. PERKIN TRANS. 1; 1235-8 (1993)
| Quote: |
Piperonyl Bromide- Piperonyl alcohol (101.44g, 0.067 mol) was added portionwise to HBr (49% aq. 100 mL), and the resultant suspension was
allaowed to stand at room temp for 2h. DCM (1L) was then added, and the organic layer seperated. The aq layer was extracted with DCM (3x 800mL), and
the combined organic extract was washed with water (2x500mL) and saturated aq NaHCO3 (3x500mL), dried and concentrated to yield the crude bromide
(123.63g, ca. 85%), which was sued without further purification. An analytical sample was prepared by recrystallisation from light petroleum,
mp 46-48°C (lit. mp 48°C) [NMR]. |
Or where you talking about bromomethylation? I think it is done in basicly the same conditions, with even more dilute acid at RT, so the HBr won't be
such a problem for the ether bridge I suppose. But the very activated ring might cause di-halomethylation to some extent? Well, again it doesn't seem
that problematic considering the high yields obtained in the refs you kindly provided.
EDIT: Considering that I want to use the benzyl halides for AcAcoEt alkylations in acetone and a weak base (carbonate), I prefer betting on the
bromide which might be more reactive in these conditions, considering the preparation of the chloride or the bromide are very simialr and I suppose
pretty much as efficent. But, if I had to go via halomethylation, I would do a first try with chloromethylation accoridng to the article you posted,
and eventually try bromomethylation as the conditions are more practical and the bromomethyl methyl ether less volatil that it's counterpart (not like
I was going to prepare before hand, be reassured ).
I will report back when i get time to start this.
[Edited on 1-10-2008 by Klute]
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
smuv
National Hazard
Posts: 842
Registered: 2-5-2007
Member Is Offline
Mood: Jingoistic
|
|
I was worried about ether cleavage during bromomethylation. Of course the procedure you posted shows that my concerns were not warranted.
With these reactions there is always some dihalomethylation additionally the formation of derivatives where the halomethylated product is attacked by
some uncreated substrate (like a Friedel-Crafts between product and substrate).
I have seen a few examples of bromomethylation of activated substrates in literature, they all seem to use HBr in AcOH along with paraformaldehyde. I
am not sure why these conditions were used instead of aqueous HBr, then again this is just what I have stumbled upon, I have never extensively
researched this subject.
PS I never knew acetoacetic ester synthesis could be preformed under such mild conditions.
"Titanium tetrachloride…You sly temptress." --Walter Bishop
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
See patent US 1 094 417 for an example, where AcAcOEt is alkylated with p-MeOBnCl in ~50% isolated yield. I guess conventional RONa/ROH conditions
would be prefered.
Do you still ahve the bromomethylation refs at hand? I remeber reading one or two myself, the reaction looked very practical and pretty high yielding.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
smuv
National Hazard
Posts: 842
Registered: 2-5-2007
Member Is Offline
Mood: Jingoistic
|
|
So here is what I have on the subject:
Eur. J. Org. Chem. 2002, 3162-3170
Bis-bromomethylation of p-dimethoxybenzene
J. Org. Chem. 1993,58, 1262-1263
General bromomethylation procedure for activated aromatics; every modern bromomethylation paper seems to reference this one.
Fuson, R. C.; McKeever, C. H. Org. React. 1942, 1, 63.
Review of chloromethylation; covers some bromomethylation and chloroethylation, propylation etc...
Organic Process Research & Development 2005, 9, 1013-1014.
Observation of Bromomethyl Ethers during the Bromomethylation of Aromatic Compounds.
P.S. its a GB patent no US; interesting though.
"Titanium tetrachloride…You sly temptress." --Walter Bishop
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Thank you very much!
What's the problem with british patent, heh?  
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
PainKilla
Hazard to Others
Posts: 306
Registered: 29-4-2004
Member Is Offline
Mood: No Mood
|
|
Attached.
Attachment: Aqueous bromomethylation utilizing PTC.pdf (96kB)
This file has been downloaded 1795 times
|
|
|
PainKilla
Hazard to Others
Posts: 306
Registered: 29-4-2004
Member Is Offline
Mood: No Mood
|
|
Attached.
Attachment: Chloromethylation of Alkoxybenzenes and conversion to benzaldehyde via sommelet.pdf (205kB)
This file has been downloaded 1318 times
|
|
|
PainKilla
Hazard to Others
Posts: 306
Registered: 29-4-2004
Member Is Offline
Mood: No Mood
|
|
Attached.
Attachment: WO2005042512 - Piperonal - chloromethylation benzyl acetate alcohol oxidation to aldehyde.pdf (620kB)
This file has been downloaded 1423 times
|
|
|
PainKilla
Hazard to Others
Posts: 306
Registered: 29-4-2004
Member Is Offline
Mood: No Mood
|
|
One more, can post more on chloro/bromomethylation if it's needed, but this covers a lot.
Attachment: Bromomethylation with paraformaldehyde and HBr.pdf (249kB)
This file has been downloaded 1072 times
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Wonderfull! thanks alot PainKilla!
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
Ephoton
Hazard to Others
Posts: 463
Registered: 21-7-2005
Member Is Offline
Mood: trying to figure out why I need a dark room retreat when I live in a forest of wattle.
|
|
klute I tried that us patent at espace and got a patent on folding gocarts any chance on some more info on this condensation as I would love to know
about it.
thanx
e3500 console login: root
bash-2.05#
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
Sorry, I thought you were refering to the WIPO patent at first..
I was pretty stunned, as I had the paper version in front of my eyes, and fell onto the bloody folding go-cart at espacent or pat2pdf.org!
I've just realized that it's a british aptent actually! Sorry for the mistake! (see, british patents kick ass
 )
Here is the link:
Method of producing 1-(4-methoxyphenyl)butanone and 1-(4-methoxyphenyl)butanone
and the WIPO patent:
[Edited on 3-10-2008 by Klute]
Attachment: 98022417.pdf (893kB)
This file has been downloaded 903 times
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
And the quoted J. Chem. Soc., Perkin Trans. article
I haev found more info on the acetoacetate condensation, and will post the article as soon as i gather them. I have found a patent where a michael
addition very similar to a claisen, except that a Mannich base is used instead of a alkyl halide (forming the alkene in-situ), using sodium
isopropoxide in IPA.
There also a seemingly very interesting article on Claisen via ptc in aprotic solvents. I will post all this in a related thread, as I'm deviating
from the thread subject here..
[Edited on 3-10-2008 by Klute]
Attachment: Perkin1_1993p1235.pdf (520kB)
This file has been downloaded 1257 times
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
