Sciencemadness Discussion Board - Nitroethane via NaNO2/DMF

Nitroethane via NaNO2/DMF

RosarioHeis - 27-3-2017 at 18:49

Hi! I recently follow this classic prep and obtained the following mixture.

I let this react for 3 days because didn't had time to do the extraction.

My question is, what would happen if i try a fractional distillation rather than diluting with water and extraction with ether?

I can't find any reference for a procedure like this and i don't know if it's going to explode or something.

byko3y - 27-3-2017 at 19:20

You will get no or almost no product. Nitroethane decomposes under action of ethyl nitrite and sodium nitrite combined.
Extraction is the most tedious part of the whole procedure, due to the fact there's a lot of goddamn DMF.

Melgar - 27-3-2017 at 19:37

Sounds like a good way to inadvertantly make n-nitrosodimethylamine. I'm assuming that flask is double-sealed at the top, and that you'd never even entertain the thought of using any nitroethane from that reaction to do something as stupid as synthesize an amphetamine salt for human consumption.

byko3y - 27-3-2017 at 21:05

Nitrosamines decompose above 140 C, thus simple heating is enough to destroy the dangerous compounds. However, 140 C is close to boiling point of NDMA, and its vapors are equally toxic.
Also, I've just realized now know what was the source of the yellow color I've got from my nitroethane experiment long time ago. This shit has almost no odor. Thanks god I'm not stupid enough to die from this crap.

clearly_not_atara - 28-3-2017 at 00:10

>classic prep

>can't find a ref

Lol where do people get these dumb ideas. I've literally never heard of this working. Which is why it's not a classic prep it's an urban legend and the only version of this that works is in polyethylene glycol. To top it off PEG is available on eBay and yet you idiots still can't get it through your thick worthless skulls.

Also idk how you'd make NDMA like this lol. I've actually tried to find procedures for formamides oxidation and they're not a thing. Pretty sure NO2 is yellow though. Please move to detritus there will never be anything good from this thread, this procedure, or this poster

[Edited on 28-3-2017 by clearly_not_atara]

Cryolite. - 28-3-2017 at 10:34

>works in polyethylene glycol

That's funny, considering the only place I've heard that is from you talking about it. Care to share a ref?

As far as I know, the only known confirmed way to make these small nitroalkanes from the haloalkanes is under PTC conditions (although even here I'm not completely sure if it generalizes, since the smallest example that paper had was 1-propyl bromide, and the corresponding nitrite is a liquid in that case)

Also yay 100 posts

[Edited on 28-3-2017 by Cryolite.]

[Edited on 28-3-2017 by Cryolite.]

clearly_not_atara - 28-3-2017 at 11:11

See "Improved chemoselective, ecofriendly conditions for the conversion of primary alkyl halides into nitroalkanes under PEG400", over 500 downloads from SM at time of posting. Yes, 3-chloropropyl is the smallest one tested, but that is pretty small.

Quote:

It should be noted that only traces of alkylnitrite could be observed (2–6%, detected as the correspondingalcohol13 byGC-MS).
[...]
A mixture of PEG400 (2mL) and NaNO2 (1.5–3mmol , Table1) was stirred for 3 h at room temperature, then the halide 1 (1 mmol) was added and the reaction was stirred for the appropriate time (Table 1). Finally, the solution was treated with 2 mL of cyclohexane and stirred for additional 5 min, then the stirring was stopped and the upper layer was transferred into another flask; the same procedure was repeated another 3 times (4 × 2 mL). Most of the cyclohexane is, then, removed by distillation (and reused), while the residue is directly charged on a chromatographic column (EtOAc/cyclohexane) giving the pure product 2.†

EDIT: apparently some things have been left out of the popular consciousness:

Quote:

The addition of urea to DMF considerably increases the solubility of sodium nitrite, and, in reactions employing secondary alkyl iodides, this is all that is required to provide the yields listed in Table I. With secondary bromides, and also cyclopentyl and cycloheptyl iodides, it becomes desirable not only to add urea but also a nitrite scavenger. Compounds such as phloroglucinol, catechol, and resorcinol can be used for this purpose; of these, phloroglucinol is the most effective
[...]
[Phloroglucinol] reacts rapidly with nitrite esters to form a deeply colored material, presumably nitrosophloroglucinol, which is readily soluble in water and non-volatile, thus making facile the separation of pure colorless nitro compound. On the other hand, catechol allows nitrosation of the nitro compound a greater chance to compete...

Apparently the reaction requires phloroglucinol to produce a clean product. The product produced with catechol is noticeably discolored. There are not even descriptions of the product obtained without a scavenger. This explains why there have been so many failures, since as we all know the nitro compound reacts with the nitrite ester.

[Edited on 28-3-2017 by clearly_not_atara]

PirateDocBrown - 28-3-2017 at 11:30

Why would you go this route? The Meyer reaction can be done in diethyl ether and would work fine for EtNO2. This is just a waste of DMF.

Cryolite. - 28-3-2017 at 11:36

The Victor-Meyer necessitates a tedious recycling of the waste silver halide back to silver nitrate. It does work, though.

RosarioHeis - 28-3-2017 at 11:43

here's the followed ref
http://pubs.acs.org/doi/abs/10.1021/ja01588a059

> NDMA? Melgar give us one about that

clearly_not_atara - 28-3-2017 at 11:50

Quote: Originally posted by RosarioHeis

here's the followed ref
http://pubs.acs.org/doi/abs/10.1021/ja01588a059

> NDMA? Melgar give us one about that

See above, the abstract does not mention that the reaction is only successful in the presence of phloroglucinol as a nitrite scavenger and preferably urea as a solubility enhancer. I apologize for my tone, I was drunk last night.

[Edited on 28-3-2017 by clearly_not_atara]

PirateDocBrown - 28-3-2017 at 11:51

Quote: Originally posted by Cryolite.

The Victor-Meyer necessitates a tedious recycling of the waste silver halide back to silver nitrate. It does work, though.

Tedious is a matter of opinion. I love that kind of stuff.

Cryolite. - 28-3-2017 at 12:16

Such a shame that DMSO reacts with ethyl bromide...

Why is it that nitrite esters don't form in PEG anyways? And also, why has no one tried this before to get nitroethane?

Melgar - 28-3-2017 at 12:52

I mostly wanted to scare OP, but if there's any water present, then the hydrolysis of DMF is possible in both acidic and basic conditions, producing dimethylamine in either case. Dimethylamine can react with nitrite ions to produce NDMA. Granted, I don't know how stable NDMA would be in these conditions, and I don't know for sure that it'd be formed in significant quantities, which is why I phrased my post "Sounds like a good way...", as in, "this seems to be a potential side reaction, at first glance."

byko3y - 28-3-2017 at 16:52

Well, it's sad to say, but the combination of alkyl nitrite and alkali nitrite is a good nitrosation agent, just as good as a combination of alkyl nitrite and amine, which also react with each other without any additionalr reagents, yielding nitrosamine: The kinetics and mechanism of the aminolysis of phenethyl nitrite

Cryolite, let's calculate for a minute a price of making 1 kg of nitroethane. Suppose we have 70% yield of nitroethane and recycle 95% of silver. 1kg / 75 / 0.7 = 19 moles of silver nitrite required, almost 1 mole of silver is lost, which is approx 100 g.
100 g of silver for every 1 kg of nitroethane. This costs almost like 30 L of anhydrous 99.8% DMF from sigma, while the latter can also be recycled (dunno about PEG).

Nitrite esters are formed in the PEG.

[Edited on 29-3-2017 by byko3y]

Melgar - 29-3-2017 at 00:06

Quote: Originally posted by byko3y

Well, it's sad to say, but the combination of alkyl nitrite and alkali nitrite is a good nitrosation agent, just as good as a combination of alkyl nitrite and amine, which also react with each other without any additionalr reagents, yielding nitrosamine.

Additional reading indicates that pure DMF is odorless, and that its typical odor actually comes from dimethylamine impurities. Meaning that this is probably the last solvent you'd want to form nitrous acid in. There's a reason there haven't been any papers on this type of reaction since the fifties.

OP: I shouldn't have to say this, but don't go sniffing your reaction mixture to see if it smells of dimethylamine.

clearly_not_atara - 29-3-2017 at 00:35

Byok3y: It's a rounding error when you consider that nitroethane makes triple its weight in molly which goes for $3-5 per gram. PTCs or anethole or whatever are cheaper but its not stopping the flow of spice.

The thing is that from the chemists' perspective it's senseless to report that you've successfully made nitroethane or acetic anhydride etc in commercializeable quantities. All you're doing is drawing a big fat target on yourself, "here, LEO, I use morpholine, so track morpholine, k?".

If you're doing experiments on your own time, it's a fun adventure to go to some pawn shops and buy old pieces of jewelry to digest, and it's probably what I would do if I wanted to make nitroethane. But if you're on a payroll your boss is probably Mexican and he might bring you some straight from a rock, I hear they mine it down there after all.

[Edited on 29-3-2017 by clearly_not_atara]

Nitroalkane via NaNO2/PEG-400

RosarioHeis - 5-4-2017 at 19:50

Hi! Any one tryied this with small alkyl bromides? Or any ref who does? There's not much information.

- Improved chemoselective, ecofriendly conditions for the conversion of primary alkyl halides into nitroalkanes under PEG400
- Doi: 10.1039/B805985C

Corrosive Joeseph - 5-4-2017 at 21:09

Here is your ref...............

/CJ

Attachment: Primary Alkyl Halides into Nitroalkanes with PEG400.pdf (87kB)
This file has been downloaded 667 times

[EDIT] - Just realized this was posted here just over a week ago in a VERY similar thread started by the OP.

[Edited on 6-4-2017 by Corrosive Joeseph]

byko3y - 6-4-2017 at 00:29

The only one thing that's really interests me here is: can PEG be recycled?

Corrosive Joeseph - 6-4-2017 at 00:44

Mentioned up thread. Here's the full paper................

/CJ

Attachment: A New Method of the Synthesis of Alphiatic Compounds.pdf (661kB)
This file has been downloaded 477 times

[Edited on 6-4-2017 by Corrosive Joeseph]

RosarioHeis - 6-4-2017 at 08:18

Quote: Originally posted by Corrosive Joeseph

Here is your ref...............

/CJ

[EDIT] - Just realized this was posted here just over a week ago in a VERY similar thread started by the OP.

[Edited on 6-4-2017 by Corrosive Joeseph]

It's the same i've posted. I'm wondering about some new one, or if any one tryied this out.

Quote: Originally posted by byko3y

The only one thing that's really interests me here is: can PEG be recycled?

It's said that you can re use it adding just 1 extra Mol of NaNO2.

clearly_not_atara - 6-4-2017 at 10:43

Apparently phloroglucinol can be made by dehydrating inositol. This was crucial in inactivating ethyl nitrite (which destroys nitroethane) in the DMF reaction. Much less EtONO is produced here (and the authors did not use phloroglucinol), but I think it wouldn't hurt to use an inhibitor, since we're usually using less equipment than the professionals.

Inositol itself is available as a dietary supplement, and also happens to be one of the better-tasting low-calorie sweeteners (I used to put it in my coffee).

Corrosive Joeseph - 6-4-2017 at 13:09

"Inositol or cyclohexane-1,2,3,4,5,6-hexol is a chemical compound with formula C6H12O6 or (-CHOH-)6, a six-fold alcohol (polyol) of cyclohexane. It exists in nine possible stereoisomers, of which the most prominent form, widely occurring in nature, is cis-1,2,3,5-trans-4,6-cyclohexanehexol, or myo-inositol (former names meso-inositol or i-inositol).[2][3] Inositol is a sugar alcohol. Its taste has been assayed at half the sweetness of table sugar (sucrose)"

From - https://en.wikipedia.org/wiki/Inositol

I'm not really finding much on the acid dehydration except this reference-less mention -
http://www.sciencemadness.org/talk/viewthread.php?tid=73311

Which doesn't look promising to be honest, but I could be wrong.......... Maybe phosphoric is an option...........? High dilution..............?

It looks messy............... Nothing concrete turning up here............ Yet

/CJ

[Edited on 6-4-2017 by Corrosive Joeseph]

[Edited on 6-4-2017 by Corrosive Joeseph]

RosarioHeis - 6-4-2017 at 13:29

Also Catechols can be used to destroy nitrite ester, some phenol and peroxide. But this prep using PEG it's so green that deserves a try

Corrosive Joeseph - 6-4-2017 at 14:08

You might also like this -

/CJ

Attachment: Polyethylene Glycol and Solutions of Polyethylene Glycol as Green Reaction Media.pdf (453kB)
This file has been downloaded 440 times