Sodium Bichromate synthesis questions

[sYnThOmAtIc]

Post 484576

(sYnThOmAtIc: "Reuse?", Chemistry Discourse)
ning: I am very well aware of it's nastiness! And it's expense. That is why this thread is so long. It is almost entirely about the regeneration of the Cr species for reuse. The main point was answered by terbium.

That being said, would you like to post a method of producing aldehyde from anethole? Cause I would damn sure appreciate it.. No, really!! Prefferably not on the 10g scale either. So if you have a method with reference for oxidation of anethole on the 50-200g level please post it...

20 g anise oil was suspended in a mixture of 150 mL water and 30 mL conc. sulfuric acid; addition of 55 g sodium bichromate at such a rate that the temperature did not exceed 40°C. The reaction mixture was extracted with 4 x 125 mL toluene and the solvent evaporated. The residual oil was vacuum distilled to yield 9.1 g anisaldehyde.


Know of a better way? With specific results of anisaldehyde.

[ning]

https://www.thevespiary.org/rhodium/Rhodium/chemistry/benzaldehydes.kmno4.html

https://www.thevespiary.org/rhodium/Rhodium/chemistry/alkene2aldehyde.kmno4-thf.html

Post 474827

(hypo: "wanted:otc _and_ largescale PhCH=CHCH3 -> PHCHO", Methods Discourse)

Post 444195

(GC_MS: "Contest: anise oil as MDMA precursor", Methods Discourse)


I don't think it's fair of you to expect an article giving the exact conditions for your exact oxidation in exactly the scale you want, with no experimentation on your part. Especially when you are willing to do all kinds of experimentation to make dichromate.

Clandestine chemistry can be green chemistry too.
I wouldn't want to trip on anything that caused the poisoning of a river somewhere. Bad karma, ya know?

I will continue to explore beilstein for interesting articles related to this.

If you were going to process enough material to make chromium recycling worthwhile, I think an ozone generator would bee a worthy investment. Think about the cost of the precursor chemicals (-->$0). Ozonolysis yields are supposed to be quite good.

[sYnThOmAtIc]

Your right, it's not fair. Plus, if I thought I was so enclined to do so, I would experiment to find a suitable reaction on a scale that is actually worth a damn. I only see the simple bichromate being scalable. Although, I am bound to screw somthing up. Not everything is always scaled up in the same proportions as teh original reaction. I have a problem figuring out that part.

Hypo expresses a lot of shared frustrations. However, I am more partial to the V2O5 and sulphanilic acid doped bichromate. That Alumina/KMnO4 reaction looks good, but I know I would screw that up seeing as I would have to scale it 100x. Also I don't like the idea of ordering stuff like permanganate. Several places I know of require DEA form for it now.

Ozone has always looked awseome to me. I love electrolytic experiments. However, determining ozone concentration and other stuff is quite difficult. Besides my recirculator only has markings down to -20. It turns past that enough to count to about -120. This can't be right and the thermostat probably doesn't function at this setting? I have never tried to get it below -15. The ozone reaction requires temps of -80.

I have never even seen sulphanilic acid preparation or at the chem supply. Everything else it on too small a scale liek thae vanadium.

My purpose in reuse is mostly from not wanting to throw Cr salts into the enviroment. I also want to recycle it so that I can use it again. I like the idea of being able to have reusable chemicals so that lifetime stockpile of chems can be kept in a few small bottles  

Also, after reading a post in teh metals finishing forum, sodium chromate can be made by electrolytic oxidation into NaOH solution. The well known basic electrostrip. So I guess to save teh expensive H2O2, one can make the chlroide salt and electroplate it onto a carbon rod and reverse into NaOH.