Sciencemadness Discussion Board

Competence Advice

aga - 24-10-2015 at 11:11

As a noob to OC, would i be wasting my time even attempting a synthesis of indole-3-acetic acid as found in this reference :

http://www.orgsyn.org/demo.aspx?prep=CV5P0654

The target compound is indole-3-butyric acid for use as a plant rooting hormone, and the acetic version is the simplest route that i found.

If it could be synthed by such as me, are there any nasties lurking in that process that could leap out and kill someone if it went wrong ?

Crowfjord - 24-10-2015 at 11:31

You have an autoclave? Aside from pressure-related risks, and the fact that indole is really stinky, I don't see any problems with that synthesis. The procedure looks very simple. As long as you have the proper equipment, you shouldn't have any problems.

[Edited on 24-10-2015 by Crowfjord]

aga - 24-10-2015 at 11:44

Don't have an autoclave yet.

If there is a possibility that i can perform the synthesis, and the figures work out OK then i'll buy one.

Looking to root a LOT of plant cuttings.

Thanks for the advice.

Edit:

Hmm. Do i really know what they mean by 'autoclave' ?

They have always been a high-pressure steam sterilisation device in my understanding.

Is there another chemistry-specific meaning of which i am unaware ?

[Edited on 24-10-2015 by aga]

zed - 24-10-2015 at 15:33

A Parr high pressure reactor is suitable for this reaction. It gets real hot, and there would figure to be many hundreds of pounds of steam pressure per square inch. In this case, when they say autoclave, they mean....High pressure, stainless steel reaction vessel.

So yeah, without the proper reaction vessel, it would kill you.

I have however, seen papers reporting the formation of such Indole-3-acids, via the refluxing of acetic anhydride and an unsaturated acid/ester. Like EthylAcrylate, to produce the Indole-3-Butyric acid (or ester).

Indole is not stinky at ordinary temperatures. It has a pleasant floral odor.

Chloroacetic acid might serve to produce Indole acetic acid via an alternate route.

But, if you just want to play with some Indole Butyric acid, you could consider buying some.

Dirt cheap on Ebay. http://www.ebay.com/itm/Indole-3-butyric-acid-99-High-Purity...

Even small quantities are sometimes less than a buck a gram.

Can also be produced via the Fischer Indole Synthesis. 2-Methyl-Indole-3- Acetic acid may be readily produced from Levulinic acid. Sadly, it ain't much of an auxine.

[Edited on 24-10-2015 by zed]

aga - 24-10-2015 at 23:38

Oh.

Not even properly understanding the name of the equipment is an obvious sign that i should abandon this idea and just buy it instead.

Thanks for the advice.

battoussai114 - 25-10-2015 at 06:11

Assuming water vapor to be the main contributor to the pressure inside, you'd be keeping the reactor at around 40 atmospheres for almost one day. High pressure stainless steel tubing and flanges should withstand more than 100atm, for a loooong time, at the temperature the reactor would be operating.
So it should be possible to build a reactor even if you don't have equipment to machine and weld 304 stainless steel.... Though I wouldn't suggest you do it.

aga - 25-10-2015 at 07:59

As much as i'd enjoy DIY-ing a high pressure reactor (which i'm sure i could) the Risk is simply not worth the reward.

Better to attempt that synth after having at least 1 iota of experience (if at all, ever).

clearly_not_atara - 25-10-2015 at 08:59

You could do a coupling between gramine and diethyl oxaloacetate to generate an intermediate which decarboxylates to 4-(indol-3-yl)-2-oxobutyric acid.

Gramine is synthesized at stp and couplings occur via elimination of the methiodide or similar eliminations (ethyl propiolate works well) also at stp.

blogfast25 - 25-10-2015 at 09:11

Quote: Originally posted by aga  

Better to attempt that synth after having at least 1 iota of experience (if at all, ever).


Also, synths like that should never be undertaken without full knowledge of the Quantum chemistry involved. Well known, that! ;););)

aga - 25-10-2015 at 10:52

... or at least a quantum of knowledge of the chemistry involved ...

blogfast25 - 25-10-2015 at 11:07

Quote: Originally posted by aga  
... or at least a quantum of knowledge of the chemistry involved ...


It would bring solace, yes.

As it happens, the (partial) quantum explanation of the reaction isn't even very hard. :cool:

[Edited on 25-10-2015 by blogfast25]

UC235 - 25-10-2015 at 11:42

I think the synthetic route of least resistance to indole-3- acetic acid is probably the Fischer Indole Synthesis and subsequent decarboxylation of alpha-ketoglutaric acid phenylhydrazone. Still not the easiest prep out there, but workable.


Attachment: ketoglutarateindole.pdf (67kB)
This file has been downloaded 325 times

ELRIC - 25-10-2015 at 12:05

@aga

I know this is not youre target compound, but have you looked into 1-Naphthaleneacetic acid?

aga - 25-10-2015 at 13:13

Quote: Originally posted by blogfast25  
As it happens, the (partial) quantum explanation of the reaction isn't even very hard. :cool:

Sorry. Was i being denser than normal ?

Please be explainings the Quantumings.
Quote: Originally posted by UC235  
I think the synthetic route of least resistance to indole-3-acetic acid is probably the Fischer Indole Synthesis and subsequent decarboxylation of alpha-ketoglutaric acid phenylhydrazone.

The words used in OC are like alluring magical incantations.

Some words are known : alpha, acid, synthesis, of, the ...

'Decarboxylation' i appear to have Done, yet cannot imagine that it always requires just Heat to work.

keto, glutaric, phenyl and hydrazone are new spells to me.

(maybe phenyl means phenol-shaped-bit-stuck-to-another-bit)
Quote: Originally posted by ELRIC  
I know this is not youre target compound, but have you looked into 1-Naphthaleneacetic acid?

I had not. Have now.

Clearly my whole notion of getting plant cuttings to take root is a vast field of biochemical research and there is far too much to learn in a short time.

Better to just buy stuff (for now) instead of doing all that fun Learning stuff.

The Responses given here are certainly an Education, that's for sure !

.. and for that i am grateful to You all.

[Edited on 25-10-2015 by aga]

blogfast25 - 25-10-2015 at 13:33

Quote: Originally posted by aga  
Quote: Originally posted by blogfast25  
As it happens, the (partial) quantum explanation of the reaction isn't even very hard. :cool:

Sorry. Was i being denser than normal ?

Please be explainings the Quantumings.



By extremely pop...[cough!][Ahem!]...ular demand and because of Manifest Destiny and everthank, I will extend the WM/QM thread and explain it there, so don't lose the will to live! :o

Also, old answers and new questions tonite at 12 hundred UTC, old chap!

[Edited on 25-10-2015 by blogfast25]

aga - 25-10-2015 at 13:35

Excellent. Get over there and start explaining - i'll be waiting.

It would be great to see a specific application of the QM Theory.

Dr.Bob - 25-10-2015 at 14:28

Any reaction that requires that type of heat and pressure is best for after some other ones. I have done a few high pressure reactions, in both glass pressure tubes and steel parr reactors (also know as autoclaves or "bombs"). They are not cheap, all had multiple safety measures and the most modern ones are microwave reactors with thick glass vessels, pressure monitoring and high tech temperature control. Still have had problems. But they can do some neat chemistry in the best of conditions. But they are known as "bombs" for a reason...

aga - 25-10-2015 at 14:33

I agree, hence not being willing to 'just do it'.

The Remote Controlled Lab idea popped up (again) for quite a few moments when considering saying 'what the hell' and just doing it.

Building and using a RemLab<sup>tm</sup> would be very safe at all stages, apart from loading the reagents, and (most dangerous) visiting it to collect the results.

Edit:

... assuming that the results had not already exited the RemLab<sup>tm</sup> and had arrived via a ballistic mode.

[Edited on 25-10-2015 by aga]

zed - 26-10-2015 at 14:53

Rooting? Try a yogurt maker. Bottom heat.

aga - 26-10-2015 at 15:06

Quote: Originally posted by zed  
Rooting? Try a yogurt maker. Bottom heat.

Please explain.

Little_Ghost_again - 27-10-2015 at 01:44

He means try apply heat to the cuttings from the bottom.

Or you could try willow water, it contains many plant hormones. if you look at Ash or willow trees you will see tiny twigs in places that stick out around parts of the branches and trunk, theses small twigs contain large amounts of growth hormones. Stick in a blender then soak 48 hours in water and reduce to almost dry.

Bot0nist - 27-10-2015 at 13:53

At the greenhouse, only the hardest to root cuttings get any hormones. All cutting's trays are placed on tables that have a humidity shade and their trays sit upon a grid of 1/4 inch PVC through with hot water is circulated from a boiler. Over 80% success for rooted cuttings on average, for geraniums and various tropicals. So, I concur, bottom heat, and humidity, misting, etc.

[Edited on 27-10-2015 by Bot0nist]

zed - 27-10-2015 at 14:50

Yup! Bottom heat will often do it. Misting can be helpful too. Since, your cuttings have no roots at first, and they transpire H20, to prevent dessication, it can be important to keep the leaf environment humid. Another trick, is to reduce the number of leaves on your cutting. Some folks go with one leaf, and cut one half off. Right down the middle.

Perhaps you will find an old waterbed heater, at a garage sale. Don't plug it in, without a body of water over it though. Some models burn right up, without a heat sink.

Or, you could use the old temporary standby. Place an incandescent lightbulb, inside of an overturned cardboard box. Set your potted cuttings on top, and monitor the temperature, until you have it adjusted correctly.

Take precautions, to not start a fire.

[Edited on 27-10-2015 by zed]