Sciencemadness Discussion Board

Vanillin ring closure

njl - 2-2-2020 at 17:35

I'd like to preface this by saying my question definitely relates to cookery so it should be moved accordingly (if it crosses a line).

Anyway, I have a large sample of Vanillin (impulse buy) and as I was looking for something to do with it several results came up detailing its demethylation to yield products useful for amphetamine production (among other things). But after taking another look at a vanillin molecule I'm unsure as to exactly what is preventing the desired Methylenedioxy ring from forming. In other words, I don't understand why demethyleation is necessary when the methoxy group is already present. After UTFSE I saw one thread that mentioned this in which a frustrated cook asked the same question but no answer was given. Thoughts?

Other post

SWIM - 2-2-2020 at 18:06

Many answers were given.
Mostly reasons why it wouldn't work.

Good reasons. Sensible reasons.


"Whoa thanks god I don't do chemistry I wouldve died long ago." This is one of the things that poster says in that thread.

Does this inspire confidence?

One of his few other thread on here is his asking how to make acetone from urea.

Does that inspire confidence?


njl - 2-2-2020 at 18:22

....Am I missing something? What does confidence have to do with this? I am well aware of the fact that it won't work. That's the point of this post... I'm wondering why. Apparently I need glasses because I don't see a clear answer in the thread.

myr - 3-2-2020 at 11:42

Quote: Originally posted by njl  
I'd like to preface this by saying my question definitely relates to cookery so it should be moved accordingly (if it crosses a line).

Anyway, I have a large sample of Vanillin (impulse buy) and as I was looking for something to do with it several results came up detailing its demethylation to yield products useful for amphetamine production (among other things). But after taking another look at a vanillin molecule I'm unsure as to exactly what is preventing the desired Methylenedioxy ring from forming. In other words, I don't understand why demethyleation is necessary when the methoxy group is already present. After UTFSE I saw one thread that mentioned this in which a frustrated cook asked the same question but no answer was given. Thoughts?

Other post



When biota make the benzodioxole ring, I believe they indeed do start with an o-methyl phenol, and there is some set of enzymes that accomplish the closure. However, as is often the case, Nature has us beat here, and we have to start from the diphenol.

Texium - 3-2-2020 at 13:26

It's above board enough since it's only discussing why a particular reaction doesn't work. There's pedagogical value here at least, so I'm gonna move it to Beginnings.

SWIM - 3-2-2020 at 13:51


I think it won't work for the reasons listed here:

Other post

Tell me if you think any of these reasons are faulty, and why.

Start with the first answer, which explains why it won't work, and explain why you think that this is either not an answer, or is wrong.



[Edited on 3-2-2020 by SWIM]