Author Topic: Is this right? (Read 3293 times)

Ghost_Of_BT · « **on:** October 08, 2001, 04:43:00 AM »

I tried making indole-acetic-acid methyl ester and I'm not sure it worked. I tried making an anahydrous 3% HCl in methanol solution but I had trouble measureing the amount of HCl in solution because as I was gassing alot of methanol evaporated. Because of this, I might have added too much acid. When I added IAA, the solution quickly turned purple. Does that sound right? I'm prety sure that means the IAA was destroyed, but I'm not sure. I heated the solution for a couple hours. I evaporated a sample and got a thick purple oil. What is this? Do you think it's the IAA ester or what?

Ghost_Of_BT · « **Reply #1 on:** October 08, 2001, 05:04:00 AM »

I just looked it up and I found that IAA methyl ester is a solid with melting point of 50C. Do you think my problem was to much acid (I was told that indoles are sensitive to strong acids). How sould I do this?

terbium · « **Reply #2 on:** October 08, 2001, 05:58:00 AM »

Do you think my problem was to much acid
Or maybe oxygen? It would probably be good to try this with flushing with inert gas prior to adding the acid.

Ghost_Of_BT · « **Reply #3 on:** October 08, 2001, 07:00:00 PM »

I didn't think about that. Instead of gassing, could I add aquious HCl to the methanol and dry the solution over MgSO4? Or will that remove some of the HCl along with the water? It seems the bubbling causes more methanol to evaporate because at some point during the gassing the solution lost weight since the previous reading. So I may have made a 30% acid solution wich was way too strong.

amalgum · « **Reply #4 on:** October 08, 2001, 09:28:00 PM »

You can buy the methyl-ester cant you? Or are you trying to save money?

Ghost_Of_BT · « **Reply #5 on:** October 08, 2001, 10:25:00 PM »

The companies that I know of who dont ask for business liscences dont carry it. It's nice to save money also.

Lilienthal · « **Reply #6 on:** October 08, 2001, 10:37:00 PM »

Every beginner should use TLC. It's the only simple & fast procedure to tell you what happened in a reaction.

I wouldn't expect a quantitative degradation. But you need only catalytically amounts of acid...

And usually you use the weaker sulfuric acid or para-toluene-sulfonic acid. In general indoles are very susceptible to strong acids.

Ghost_Of_BT · « **Reply #7 on:** October 08, 2001, 11:00:00 PM »

Since you say you dont expect much degredation, do you think the product I obtained is mostly the ester? Is the color change normal? Also, will water react with the ester? When I added water to a sample of the oil and boiled it away, some crystals where formed.

Lilienthal · « **Reply #8 on:** October 09, 2001, 12:55:00 AM »

You must do a base extraction to remove unreacted acid. In most reactions tiny amounts of dark colored byproducts are formed.

terbium · « **Reply #9 on:** October 09, 2001, 06:48:00 AM »

Also, will water react with the ester? When I added water to a sample of the oil and boiled it away, some crystals where formed.
If you had the ester dissolved in toluene and did some washes with 5% NaOH solution and then water that should be ok but boiling it in water sounds questionable.

Ghost_Of_BT · « **Reply #10 on:** October 09, 2001, 05:05:00 PM »

So that's how I should extract the ester? By adding the methanol solution to toluene and washing with NaOH and water? OK, here's the proceedure:
reflux IAA in an access of 1% H2SO4 methanol solution for a couple hours. Add the solution to double volume of toluene. Wash with 5% NaOH folowed by water. Evaporate toluene to obtain the ester.
Any problems with that? The IAA ester will stay in the toluene while every thing else will be washed away, correct?

Lilienthal · « **Reply #11 on:** October 09, 2001, 08:13:00 PM »

Recover starting material by acidifying the washing solution. 0.1% - 0.5% H₂SO₄ may be better - it's a catalyst. Otherwise it sounds ok.
It would be better to distill off and collect the methanol and later the toluene.

amalgum · « **Reply #12 on:** October 09, 2001, 10:25:00 PM »

So, I guess your trying to dream trytophol right? If you are, let us know how the reduction went. I'm curious, besides it might help any furture dreams of mine (and anybody else for that matter).

Ghost_Of_BT · « **Reply #13 on:** October 11, 2001, 05:06:00 PM »

If I were to make tryptophol, I would use IAA directly (like Lilienthal says). My initial plan was to make tryptophol and react it with PBr3 but I screwed up making PBr3 (the bromine wasn't dry enough). So now I am trying to make the ester, react with dimethylamine followed by LAH.

amalgum · « **Reply #14 on:** October 11, 2001, 09:42:00 PM »

Oh I see. Well let us know how your dream went anyhow.

PolytheneSam · « **Reply #15 on:** May 19, 2002, 03:44:00 PM »

Here's something from

https://www.thevespiary.org/rhodium/Rhodium/chemistry/psychedelicchemistry/chapter3.html

Alternatively, dissolve 220 g 4-benzyloxy-3-indoleacetic acid (or equimolar amount other indoleacetic acid) in 2 L absolute methanol and reflux six hours in the presence of 20 g Dowex 50x8 sulfonic acid resin. Filter (decolor with carbon if desired) and concentrate below 35ø until precipitation starts; then cool to precipitate and filter to get 200 g of the methyl ester. Add 200 g of the ester to 600 ml 40% aqueous methylamine over twelve hours with vigorous stirring. Filter, wash precipitate with water and dry to get 187 g of the N-methyl-acetamide (reflux two hours in 500 ml benzene to remove unreacted ester). 24 g of the acetamide in 300 ml tetrahydrofuran is added dropwise to 10 g lithium aluminum hydride in 300 ml tetrahydrofuran; reflux ten hours, cool to 15ø and add dropwise with stirring 50 ml ethyl acetate. Reflux two hours and proceed as above to get 15 g (II) or analog.

What is that Dowex 50x8 sulfonic acid resin? Could you use sulfonated polystyrene (made from polystyrene and sulfuric acid)?

http://www.geocities.com/dritte123/PSPF.html
The hardest thing to explain is the obvious

terbium · « **Reply #16 on:** May 20, 2002, 12:51:00 AM »

Yeah, any sulfonated polystyrene resing should substitute for the Dowex resin. It is being used as an acid catalyst for the esterification. The nice thing about using an ion exchange resin for this is that it is easily, mechanically separated from the reaction mix.

The big question is - will this work with dimethylamine instead of methylamine. I think that someone here, Lilienthal perhaps, has said that this won't work with dimethylamine.

Edit
It wasn't Lilienthal, it was Greensnake and Ritter:

Post 271226

(Greensnake: "Re: Indole Grignards", Tryptamine Chemistry)

Post 272175

(Ritter: "Re: Indole Grignards", Tryptamine Chemistry)