Sciencemadness Discussion Board

High Pressure PTC Methylenation of Catechol

Ephesian - 14-8-2012 at 09:28

My first post is concerning British Patent 1,518,064 taken from erowid.com. However, with hours of searching...no detailed manuscript of the process, just a reference to erowid. Not to bash the site in its entirety but I'd hate to put ware-and-tare on my Parr reactor amongst my DCM, TBAB and catechol. If someone has a detailed document of this patent I will confirm or/ debunk this patent in its claims to producing benzodioxole.

Document Found


My further plans with this material:

Vilsmeier-Haack reaction with thionyl chloride (US4157333) in production of piperonal.

without further adieu I welcome myself to Sciencemadness.org




[Edited on 15-8-2012 by Ephesian]

kristofvagyok - 14-8-2012 at 10:08

Quote: Originally posted by Ephesian  
My first post is concerning British Patent 1,518,064 taken from erowid.com. However, with hours of searching...no detailed manuscript of the process, just a reference to erowid.

Just found the mentioned patent in 2 mins.

It is easy, just add some catechol, water, DCM, TBAB and some NaOH to an autoclave and rock it.

But I think that this was described somewhere on the forum. It's not that "complicated".

P.S.: your ideas to make such things... It's just a shame, this is for people who have no ideas. Find something useful.

Ephesian - 14-8-2012 at 10:36

Tis a shame...Fortunately here on SM.org my ideas aren't bound by any non disclosure agreement clauses. So for practicality purposes I'll invest in my time here researching and implementing methods to produce those "useful chemicals" I'm almost positive a majority of the enthusiasts/chemists...and let's not forget "drug cooks" want detailed info about.


P.S pretty please a URL to the patent? :) I'm getting a patent for box lining!

[Edited on 14-8-2012 by Ephesian]

[Edited on 14-8-2012 by Ephesian]

Ephesian - 14-8-2012 at 11:12

I found it en Francais! Tres excitant! Here we go sciencemadness!

Nicodem - 14-8-2012 at 23:07

Quote: Originally posted by Ephesian  
P.S pretty please a URL to the patent? :) I'm getting a patent for box lining!

I would be worried of someone working with potentially dangerous equipment, if he demonstrates such inadequate competence like the inability to find a patent application with the reference already given.
(It took me 12 seconds (by counting) to find the patent application.)

In any case, the Example 1 describes the pressure goes up to 2.4 bar at 70 °C, so that just about any autoclave can handle it, as long as you can maintain the temperature at these safe levels.

Ephesian - 15-8-2012 at 04:25

Nicodem I found the patent (take a deep breath), my laziness and/or technological incompetence does not supersede my competence in the laboratory, hopefully :)

Ephesian - 21-8-2012 at 02:41

A few questions before I begin today...

The literature (patent) states the catechol and caustic solution be added in stages at a temperature of 70 C. To my understanding this is to prevent the formation of by-products by keeping the concentration of catechol low in the reaction mixture ( such as polymerization b/w catechol). However my reactor does not have a fill port. So what is a healthy way around this? My only idea is to leave the lid off to the reactor as it comes to temp and add the catechol in molten state along with caustic in small shots. Then cap it and let it stand for 4 hours as the patent suggests. What is the rate of this reaction? When is polymerization more likely to occur? (I would think early on in the reaction, as concentration of dihalomethane to catechol ratio is much higher)

[Edited on 21-8-2012 by Ephesian]

DH2 - 25-5-2013 at 10:38

Is it possible to methylenate catechols using the TBAB/NaOH/DCM/H2O procedure without an autoclave? The journal article states that the reaction can take place between 30 and (I think) 120 degrees. Obviously DCM has a BP of a whopping 40 degrees so I'm assuming this could be run without an autoclave (albeit with an extended reflux time.)

Any input on this? There's also another similar procedure that uses cetrimonium bromide, but the surfeit of caustic water employed in that for such a pittance of catechol (1 L for .1 mol of catechol -- WTF?) has me leaning towards the TBAB method.

Any advice is greatly appreciated.