Sciencemadness Discussion Board

Mw reactions-catechole methylation

daeron - 26-3-2005 at 05:43

reading one of Joe_aldehids posts in some other forum reminded me of a microwave catechole methylation that one friend of mine mentioned a long time ago.Unfortunately i searched high and low for some info but found none.Has anyone heard of this methylation method?
thanx in advance

joe_aldehyde - 26-3-2005 at 06:29

it wasn't microwave but ultrasound promoted methylenation. i have the files, DO pm me and i can send. i guess posting the method here isn't allowed as it is directly related to controlled compounds.

Darkfire - 26-3-2005 at 09:48

Its allowed.

"Ultrasound promoted methylenation of catechole..." is perfectly fine.

"I wanna make meth from some drian opener and pills, he1P m3 !!!" Is what we dont wanna see.

joe_aldehyde - 26-3-2005 at 10:11

i'm sorry, i messed things up. it's actually a solvent-free microwave promoted methylenation which takes place in presence of a solid phase catalyst (Clayfen or Clayan). the paper is available here (not free of charge of course)

plus, the free one is here:!8'%5D%5CY(7%5C%23S5%3D%3C6QPH%3D29%23%3C%0A

have fun

daeron - 26-3-2005 at 10:46

heeey joe-thankyouthankyouthankyou
I knew i wasnt hallucinating(not then anyway:D).
aarghh!! the free link doesnt work-at least i have a name of the article...
Ive pm-ed you my email,so if you can send me the article,i would appreciate it greatly

CherrieBaby - 27-3-2005 at 08:03

I hate to be rude, but that URL was never going to work. Can you send this article to please?

I'd send you a PM but that isn't working either.

joe_aldehyde - 27-3-2005 at 13:54

i hate to be honest, but in this case the URL was gonna work for sure. anyways, the related HTML version for the pdf found by google has already been directed to daeron.

CherrieBaby - 27-3-2005 at 20:51

I asked for it and you're not providing.

So are you refusing to let me have a copy of this article?

joe_aldehyde - 28-3-2005 at 09:09

i don't have the link anymore, ask daeron please.

daeron - 28-3-2005 at 10:27

CherryBaby ive sent you a PM.
Joe I have sent you my reply to your questions to your email,but i was slightly intoxicated so i dont know if ive typed in the right email..
kids dont do other kids :-))

joe_aldehyde - 28-3-2005 at 10:45

got it, daeron. thanks, we'll stay in touch.

CherrieBaby - 30-3-2005 at 23:33

No. No email for me.

Well I trudged off to the library to read this book only to discover scanty details of the process (page 156 in 'Microwaves in Organic Synthesis', A. Loupy (ed), ISBN: 3527305149, p. 159). They referenced a paper by Varma who then referenced a conference paper. A. Vass, J. Toth and E. Pallai-Varsanyi, 'Effect of inorganic solid support for microwave assisted organic reactions', OR 19, presented at the International Conference on Microwave Chemistry, Prague. Sept. 6-11, 1988.

What is meant by OR 19, in this context?

Here are the details from the Varma paper:

'Solvent-free organic syntheses, using supported reagents and microwave irradiation', R. S. Varma, Green Chemistry, 1, Feb. 1999, pp 43-55.

The details are on page 53:

Methylenation of 3,4-dihydroxybenzaldehyde

3,4-dihydroxybenzaldehyde undergoes methylenation rapidly in the presence of a phase transfer catalyst on a benign calcium carbonate surface; presumably the bonding of the vicinal hydroxyl groups is low thereby enhancing the reaction with the alkylating agent under solvent-free microwave irradiation:

3,4-(OH)2:C6H3-CHO + CH2I2 --> Piperonal (Conditions, on CaCO3 solid support, TBAB (PTC), MW).

Loupy et al give details which Varma omits: 3 mins., 157C, 95%.

So, if Loupy et al. knew these other details from conference paper then why didn't they reference that paper? Sloppy bastards.

Comment: The surprising thing about this is that no strong base is needed.

joe_aldehyde - 31-3-2005 at 00:01

the missing base is indeed interesting an interesting fact, i have to admit. maybe the CaCO3 does that.
temp. mentioned in the paper is 157 deg. c which is the mp of protocatechualdehyde...

would be nice to know the exact setup. maybe small pieces of CaCO3 wet with PTC (i would prefer Aliquat336 as it sits on the shelf), put together with protocatechualdehyde and BrMeBr in a flask and then irradiated would do it. hah!
recovery SHOULD be easy, because only the unreacted phenolate is soluble in water after treatment with base, so extraction with an NP solvent has unreacted BrMeBr, PTC and piperonal in it. could be used right away for knoevenagel condensation, ptc and BrMeBr sure won't hurt. bp. of piperonal is about 236 deg.c, bp. if Aliquat 336 is 225 deg.c and bp. of Dibromomethane is 98 deg.c, so a quick distillation will be sufficient.
bisulfite adduct of piperonal could help while removing PTC with NP solvent (Aliquat 336 has a solubility of 10g/L@20deg.c in water)

opinions please! i'm a novice :)

daeron - 31-3-2005 at 00:15

cherrie ive sent you the email,if you havent recieved it jet email me and ill send it again


joe_aldehyde - 31-3-2005 at 00:39

i dare say that the paper about solvent free syntheses is full of useful stuff for the clandestine chemist.

2.8.3. Side chain nitration of styrenes—preparation of
b-nitrostyrenes. <- might work with y-methylstyrenes, too. (63 R. S. Varma, K. P. Naicker and P. J. Liesen, Tetrahedron
Lett., 1998, 39, 3977.)
somebody look this up, please. i would love to try it on my own, just need some more info. if it can be used to make beta-nitro-phenylpropenes, what a beautyful thing it would be. i guess it still is an a,b-unsaturated compound, right? i wonder where the H+ from the alpha-carbon goes. shouldn't it be beta-phenylnitroethane after the reaction?

2.8.7. Methylenation of 3,4-dihydroxybenzaldehyde

2.8.5. Eugenol isomerization (sure works for other propenylbenzenes, too)

CherrieBaby - 31-3-2005 at 01:13

But these two have been known about for a while. I think the papers, or summaries, were posted to the old hive. I can dig them out soon.

2.8.3. Side chain nitration of styrenes
2.8.5. Eugenol isomerization (sure works for other propenylbenzenes, too)

I din't know about :

2.8.7. Methylenation of 3,4-dihydroxybenzaldehyde

I only just found out about that. I would use CaCO3 powder, mix in all the reactants and catalyst very well so that they form a slurry. Smear the slurry around the sides of the beaker or flask so that it can all recieve microwave exposure. What about the heat setting? I imagine full heat setting.

daeron - 31-3-2005 at 01:15

oh yeah about that ref from varna paper...there maybe something wrong with the procedure,swims close friend and colegue had tried is a few times(10 times!) and came up with nothing(using a regular MW)...maybe thats why it wasnt ref.ed?
and the 3min heating time is suspicious too,cos swims friend found other refs with rxn times of 15 and more mins.Any thoughts?

PS Joe youre a very good novice:)..BUT you have made a very small but crucial mistake..the catalyst!Different catalysts,different rxn times,different may have to change the procedure a bit(?)kinetics my dear boy,kinetics...again just a thought because if the kinetics are the same your extraction will work like a charm(a..336 and tbab have very simmilar solubility)
....ok checked it with proper "authority" a..336 can be used instead of tbab,but rxn times are slightly different...sorry for the ramblings havent had much sleep:(

PPS joe can you post my mw procedure ive sent you,since cherrie or some one else might be interested in it

west side,peace out,all that ghetto shit..sun`s up but im going to bed:D

JohnWW - 31-3-2005 at 04:31

Can you post links to the articles mentioned, or attach the articles to posts, please? The reactions are hard to follow without access to the articles.

CherrieBaby - 31-3-2005 at 06:38

I'd normally say yes (to posting articles) but...

In this case I only have the Varma paper. I gives just a few lines outlining the reaction which I've already posted, more or less, word for word. The other (chapter in a book) gives some other details which I also posted (157C, 95%, 3 mins).

That's all we have. No experimental details. No theory, no discussion of mechanisms, nowt.

The actual details are presumably possessed by the people who presented that paper to the conference: A. Vass, J. Toth and E. Pallai-Varsanyi. They are the guys who did this and unless you contact them or get their conference paper I don't think you can get any more details.

joe_aldehyde - 31-3-2005 at 08:29

well, then we need to get in touch with these people. from their names i gather that they must be hungarians. lets see. maybe we can work something out. would sure be a great thing :)

daeron - 9-8-2005 at 03:09

anyone in for a bump?

joe_aldehyde - 11-8-2005 at 23:58

weren't you after the pyridine*HCl route?

daeron - 15-8-2005 at 06:38

the pyridine.hcl route was used to obtain the swim is interested in a effective mw methylation of the catechole-->corresponding methylendioxybenzene.
still havent had the time to do some playin around w PTCs and MWs...

CherrieBaby - 23-10-2005 at 03:16

I mistyped a reference. I gave the wrong date. The paper dealing with Methylenation using microwaves was:
A. Vass, J. Toth and E. Pallai-Varsanyi, Effect of inorganic solid support for microwave assisted organic reactions, OR 19, presented at the International Conference on Microwave Chemistry, Prague, Czech Republic, Sept. 6-11, 1998.

I don't know what the term 'OR 19' means but I suspect it is the number of the actual paper presented at that conference. I've discovered that there are proceedings and abstracts from the conference:

Proceedings: "Proceedings of the International Conference on Microwave Chemistry", Prague, September 6-11, 1998. (Ed. Čermák, J.; Hájek, M.; Hetflejš, J.; Včelák, J.).

Abstracts: International Conference on Microwave Chemistry, Book of Abstracts, P22, Praha, 6-11 September (1998). ISBN 80-86186-01-6

Here is the Varma article which referenced this conference:

I would be eternally grateful if anyone could get this article (the conference paper not the Varma article) for me.

I discovered this relevant document on the web:
New Synthetic Method of Aromatic Ethers under Microwave Irradiation in Dry Media, Synth. Commun. 28, 3029-3039 (1998); D. Bogdal, J.Pielichowski, A.Boron

[Edited on 23-10-2005 by CherrieBaby]

interesting patent that my help on this subject

v16 - 8-4-2008 at 14:08

Process for preparation of polyhydric alcohols

EDIT by Nicodem: If you think it is funny when you post something completely off topic to more than two years old thread you are wrong! This thread is about methylenation of catechole so if you have nothing to contribute, rather don't post at all.

[Edited on 9/4/2008 by Nicodem]

Woops, was reading this topic and this one demethlenation at the same time. reposted to proper topic. sorry for the mis-post.

[Edited on 9-4-2008 by v16]

Maja - 7-6-2008 at 04:26

What is the of purifying protocatechualdehyde ? Mine obtained from Vanillin demethylation is dirty yellow/brown...

kalacrow - 8-6-2008 at 09:08

detailed instructions there.

[Edited on 8-6-2008 by kalacrow]