POSSIBLE SYNTH ON NITROMETHANE.

[technology]

Nitromethane synthesis.

I took the liberty of posting this synth for the fact that i have read several posts concerning the level of castor oil in the nitromethane RC fuel, and not to mention the % of nitromethane in RC fuel anyway.

I hope it is useful, if not it will just fade away amoung the many others.." in the hive.

I have not performed this synth but has been extracted from a academic source.

To a mixture of 125g (1.33 mol) of chloroacetic acid and 125g of crushed ice contained in a 1000ml 2 neck RBF, add, with stirring or shaking, sufficient 40% sodium hydroxide solution to render the solution faintly alkaline. About 90ml required.

The temp should not be allowed to rise above 20'C degrees, or else sodium glycolate will form.

Introduce a solution of 91g (1.3 mol) of pure sodium nitrite in 100ml of water into the flask. insert a thermometer well into the liquid by means of a screw capped adapter fitted in the side neck. Attach a still-head fitted with an efficient condenser set for downward distillation. (the receiver should be cooled in ice-water)

Heat the mixture slowly until the first appearence of bubbles of carbon dioxide(this occurs when the temp has reached 80-85'C. immediately remove heat source".

The reaction (decomposition of the sodium nitroacetate) sets in with liberation of the heat and the temp rises to almost 100'C without further application of external heat.

Note) if heat is applied once the temp reaches 85'C the solution will begin to froth and a loss of nitromethane will occur.

Result: ~30ml of nitromethane and 40ml of water, distill over.

When the exothermic reaction apparently ceases (temp below 90'C, heat the mixture (gently) until it rises to 110'C.

transfer the distilate to a sep funnel, allow to stand for ~30min to complete the seperation of the two layers and remove the lower layer being nitromethane".

Dry it with anhydrous calcium chloride or an calcium sulphate and distil:

30g (37%) of nitromethane, bp 100-102 are obtained.

Ref: A, Vogel (1978) Vogels textbook on Practical organic chemistry.

[Bandil]

It's posted on Rhodiums site, or at least the nitroethan equalvient is there...

It's kindof a waste to make nitromethane, unless you find it totally amusing to make the stuff. It's widely available almost everywhere for a few bucks per litre.

Also, that partcular synth is quite expensive and very hard to get to work properly(swim never got more than 10% yeild with the ethane version).

Regards
Bandil

[GC_MS]

When the exothermic reaction apparently ceases (temp below 90'C, heat the mixture (gently) until it rises to 110'C

I'd be careful, and when I had to distill it over, I would probably apply a vacuum. The flash point of MeNO2 is ±36°C.

[Aurelius]

When applying a vacuum to nitro compounds for distillation, you need to be careful about how you break that vacuum as 'fume-offs' can occur.  Some of which has near-explosive violence.  do a search - get some practice, all of us can use that, at least it seems that way these days.

[Tdurden969]

Note by Rhodium: Distillation of nitromethane at atmospherical pressure is not inherently dangerous as long as you aren't distilling it all to dryness. It is not practical to vacuum distill nitromethane, as there are too big losses occuring down the drain (using an aspirator as vacuum) or into your pump oil.

From dr.drools writeup

[Aurelius]

It's good to see posts with some substance.

That's a good point- yields will be lost to distillation in this manner when dealing with the lighter weight molecules.

[technology]

Just thought that perhaps out of interest it may be valuable for some, no worries.

If you find it useful all the best.

[ragnaroekk]

Flashpoint - definition

The flashpoint is the lowest temperature, at atmospheric pressure at which a liquid gives off so much combustible vapour at the liquid surface that this vapour, when mixed intimately with air, can be ignited by a flame or spark.

This says no sparks or open fire. Somehow this applies for always for a laboratory and even for a meth kitchen regarding the acetone vapours. But sounds impressing:
"flash point"

flashpoints:
diethylether:      -40
acetone:           -20
THF:               -20
toluene:           +6
ethylene glycol:   +111

There is a difference between informational warning and steering irrational fears.

[GC_MS]

There is a difference between informational warning and steering irrational fears.

I guess you never wondered why/how full grain silo's can go *kabum* in the summer period.

The flash point should never be ignored. The definition of the ISSA (International Section for the Chemical Industry) states that flash point of an inflamable liquid is the lowest temperature at which, under prescribed conditions, vapor is evolved from the liquid in sufficient quantity that this immediately ignites on contact with an effective ignition source. Now where do you read "sparks"? Sparks are an ignition source indeed, but there are countless others, let's say a Bunsen burner or a heating mantle, or even a cigarette. Aside the flash point, there is also the autoignition temperature and the need for oxygen. If you apply a vacuum, you can keep distillation temperatures lower and keep out oxygen (to a certain extent).

[ragnaroekk]

There is no contradiction in my eyes. The dangers in handling solvents/compounds like acetone exist and everyone has to be aware of this facts. But just throwing in the "flash point" without setting this into any relation is not helpful at all.

Btw. a Bunsen burner and a cigarette belong to the "open flames" (you shouldn´t smoke in the lab GC_MS, bad habit anyways...) and a heating mantle should be halfway explosion proof (ok if you abuse it by cranking it up without load....). The selfignition in silos is NOT related to this - except you have no ventilation in your lab what I don´t hope to be true. (selfignition of coal in warships around WWI is also not related).

Did I say something against vacuum?
No.
This is the Newbee forum. Throwing in tidbits without further information here is misleading and at least bad style.

Hey! GC_MS I am in no way after you, peace! And I agree that I was perhaps to harsh in the way I expressed myself - it wasn´t intended to offend you. (ok, a little bit it was, sorry so)

RaG

[GC_MS]

Did I say something against vacuum?

Did I imply you did? I don't see where. It is just a phrase containing information why a vacuum distillation in this case might have a "double" advantage.

Hey! GC_MS I am in no way after you, peace! And I agree that I was perhaps to harsh in the way I expressed myself - it wasn´t intended to offend you. (ok, a little bit it was, sorry so)

As long as you don't make jokes about my enormous cock, it is hard to offend me verb@lly.

You should take into account though that many Bees have only   a comme-ci comme-ça laboratory, especially when it comes down to safety. This does not mean they can't make good products, before some Bee takes this offensive   .