P2P synthesis from BMK glycidate ethers

[Re186]

There is a question here, it says "the NaOH reflux step can be skipped if using the sodium salt (5449-12-7)", but if so the reaction conditions will be the same as using 41232-97-7 or 80532-66-7 directly Different, because they add distilled water in the NaOH reflux stage, 35% hydrochloric acid or 45% sulfuric acid is added on this basis, the acid concentration will be completely different from skipping this step. So what I want to ask is, if the dry solid sodium salt (5449-12-7) is used here, do I need to add distilled water according to the amount of NaOH reflux step, or directly use 35% hydrochloric acid or 45% sulfuric acid and solid Can sodium salt (5449-12-7) be mixed?

 

[G.Patton]

Hi, yes. I would recommend you add distilled water in any case.

 

[Re186]

Is the brine used for washing the extract here a saturated sodium chloride solution or a sodium bicarbonate solution or a sodium carbonate solution?

 

[G.Patton]

Brine means saturated NaCl solution. You have to wash it and get rid of acid. You also can wash with sodium bicarbonate sln. and then with brine.

 

[Re186]

alright, thank you very much

 

[blackburn]

how come after hydrolysis with HCI in get clear yellow/dark oil on top liquid.

but after separating the oil from the HCI, and washing it with boiling water, the oil settles very thickly on the bottom and becomes cloudy almost like honey.

 

[blackburn]

@G.Patton

 

[Re186]

It seems that the decarboxylation reaction has not been completed, and your product contains a large amount of carboxylic acid, which causes partial solidification after cooling down.You can observe whether this turbidity and viscosity appear after cooling, if so, then my opinion is almost the same.You can use a higher temperature to reflux or reflux for a longer time to solve this problem. In addition, the boiling point of this carboxylic acid compound is much higher than that of P2P. In theory, it can be separated by distillation, but in view of the severity of the solidification after cooling, I think It is recommended that you solve the problem of incomplete response first.During this decarboxylation reaction, carbon dioxide will be released, causing small bubbles on the surface of the reaction solution to appear like shaken soda. You can roughly judge that the reaction is over by observing when the bubbles disappear.

 

[blackburn]

Thanks you Will try it

 

[Re186]

In addition, you should pay attention to whether you mix the reactants well during the reaction. The substrate of this reaction has poor solubility in water after being hydrolyzed to carboxylic acid. It is a cross-phase reaction, so you need to use a strong stirring to Mix them as much as possible, once they are in a layered state for a long time in the reaction, it is easy to have this incomplete reaction

 

[blackburn]

ok can i continue hydrolysis and boil it longer with new HCI or do i have to throw it away and start over with new BMK?

 

[Re186]

I suggest you start over, because this way you can get meaningful experimental data and reproducible experimental conclusions

 

[Re186]

My professional experience tells me that this reaction is not very suitable for hydrochloric acid, so assuming your problem has not been solved, you can try washing the uncooled oil with hot 20% sodium hydroxide aqueous solution after the reaction. Unreacted carboxylic acids can be removed by forming sodium salts dissolved in water, and the washed product should not solidify after cooling, but it is conceivable that the yield will be very low.

 

[w2x3f5]

do in H3PO4, better works then HCl

 

[w2x3f5]

Its glycidate just without sodium, standard problem and usually its happens because HCl not so good work

 

[Heisenblack]

I have gotten the same result using phosphoric acid 85%, the temperature was max, I refluxed for about 4 hours. I think the problem was that my mixing was not sufficient, plus I stopped stirring when the reaction mixture started boiling (I honestly thought the boiling would provide sufficient mixing). I extracted the brown/dark layer with toluene, washed the extract with brine solution couple of times until the aqueous layer was neutral, then I evaporated the toluene and was left with a viscous brown liquid. When I purified this brown liquid via steam distillation,only a small fraction of light yellow p2p (maybe 2 - 5ml from 100g cas 5449) came with the water in the receiving flask, a light brown residue was left after steam distillation (see picture). I assume this is the unreacted glycidic acid?

 

[Heisenblack]

@Sweswe @G.Patton

 

[Heisenblack]

This is the p2p oil (I think) from the receiving flask , the mixture is still cloudy, I left it to separate into layers overnight (hopefully).

With the unreacted glycidic acid, I am planning to extract it and see if I can get more p2p by hydrolising again with the acid, using strong mixing. Starting from here, can I skip the NaOH step or is it necessary?

 

[w2x3f5]

Send me a private message and I'll try to help you

 

[w2x3f5]

mixing is not necessary, there are other important points

 

[G.Patton]

Hello, probably your problem is in a steam distillation?

 

[G.Patton]

Looks like a not well separated solution.

P.S. you can ask me in DM. I if for free. You don't need to pay.