Yellow nitromethane?

[Rabidreject]

Okay so I’ve been prepping to start down a whole new rabbit hole…phenethylamines.

The hardest part for me to find in my country - or even out of country, due to shipping concerns, has been the nitromethane.
The absolute best I could come up with was finding a supplier from another EU country of a 40% w/w mix of nitromethane and whatever solvent I choose.
I therefore went for DCM - both useful (once distilled a couple times) and also doesn’t form an azeotrope with the NM. Correct?

My question is this, why is it I can’t just set my mantle at 45c or whatever the low bp of DCM is and wait for it to stop boiling and for it to stop coming over, then move my mantle up to 101c for the NM to come over?
Why, when I did my first distillation of the DCM/NM mix, does it pull DCM across all the way up to 100c? At which point you obviously swap out the collection flask and then redistil it…

I get that but why does it pull it across at all temps between the bp of DCM all the way up to and then past the BP of NM?

That’s the first part of the question, the second part is, is it quite common for nitromethane to turn yellow?
I was chatting to GPT and it said that NM is clear and if it has a yellow tinge it’s an impurity - now I know it’s not always correct regarding chem questions, however, I then googled it and sciencemadness came up with people talking about it…

I intend to, of course, re-distil the NM tomorrow and then basically proceed straight to my first Henry reaction…

 

[Rabidreject]

After writing that, I ended up with pretty much clear NM, ever so slightly yellow but that came from the higher fractions at the end.
It must have just been yellow when the dude made it up because there was def nothing in there but DCM:NM
I ended up with around 400ml and a tiny puddle of basically brown starting material at this point.
I somehow ended up with like 750-800 of DCM but then I had been saving up some stuff I’d recovered a few times from a reaction so it’ll probably need a couple of distillations still.
I wish I had a UK link for this stuff as it’s essentially required A LOT for the things I’m making!

 

[Rabidreject]

Or one could LITERALLY just use the ‘methanol’ solution that comes over and one was using for blood cleaning!

I literally ran the Henry reaction on 3,4,5-TMOBA at room temp yesterday using the 9% mix of methanol and NM that I assume is the azeotrope. I used ethylenediamine and GAA as the catalyst. Up until this point, I had literally just been using this shit to clean my Glassware from time to time

Worked beautifully! Iv yet to compare yields with the NM/Ammonium Acetate method as it’s been in the fridge overnight but I was quite amazed it actually worked tbh!
Should def save me a decent amount of money…or time…or both lol