Solvent for EtBr + NaNO2 -> Nitroethane

[SpicyBrown]

In

https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitroalkane.html

regarding the synthesis of Nitrothethane from Ethyl Bromide and Sodium Nitrite, the text says DMSO can be used in place of DMF. For 32.5 grams of Ethyl Bromide they suggest 600ml DMF. How much DMSO would be used in it's place?

Thanks,
SpicyBrown

[lugh]

Kornblum's synthesis of nitro compounds {JACS 78 1497 (1955)} was done using dimethylformamide, primarily because of sodium nitrite's solubility in that solvent. Kornblum writes in note 10 that Mr. Hardles discovered that the same reaction occured in dimethyl sulfoxide just before publication, and that sodium nitrite was more soluble in dimethyl sulfoxide than dimethylformamide. Thus, unless some bee has actually done this and cares to tell you about it, you are going to have to determine this fact for yourself. Please let us know once you find out  

[ChemicalSolution]

The solubility of NaNO2 in DMSO is 20g per 100ml however in the CA publication, 250ml was used per 36g(0.52 mole) NaNO2 with 0.29 mole alkyl halide. 

All of the examples used were larger alkyl halides.  I know someone who would be interested to see how it works with ET-Br.  Anyway, most of the yields with DMF were a little lower than DMSO and the reaction time was considerably shorter with the DMSO route.  Apparently the dryness of the reaction plays a huge role with secondary alkyl halides but "not much of one" with primary halides.  So heathfood store DMSO would probably work fine.. Now if it wasn't so damn expensive!!

[terbium]

So heathfood store DMSO would probably work fine.. Now if it wasn't so damn expensive!!
Gee, I just did a little search of the Internet and found 99.9% DMSO offered for sale for less than $40.00/gallon.

[ChemicalSolution]

LOL.  After you fractionally distill nearly 1/3 volume of water off you will have a decent solvent.  Still, it's cheaper than the healthfood store stuff.  One has to wonder how *they* can sell "99.9%" DMSO at a fraction of the price of that from reputable sellers.

[terbium]

After you fractionally distill nearly 1/3 volume of water off you will have a decent solvent.


DMSO is cheap stuff. It is a byproduct.

edit:
I just found another Internet site selling 99.9% DMSO for a little over $40/gallon

[lugh]

If it's 99.9% dimethylsulfoxide how can it be 1/3 water?
Dimethyl sulfoxide is generally treated with a drying agent prior to vacuum distillation, sodium hydroxide pellets have been used sucessfully  

[ChemicalSolution]

Once you buy that 99.9% DMSO you'll see how it can be 1/3 water.  Don't bother asking for a certificate of analysis from them.  If you have a dealer that sold you 99.9% DMSO for $40/gallon then more power to you.  If you haven't used it yet, you might try distilling to make sure.  I know someone who used the bargain DMSO and ruined a batch.  Later found out it really wasn't 99.9%.  See if it freezes if your fridge.

[SpicyBrown]

Thanks everybody for your input! SWIM will of course report back here with results should they surface..

SpicyBrown