Sciencemadness Discussion Board

methyl chloride from dimethyl sulfate

6dthjd1 - 16-3-2019 at 19:20

Is it possible to synthesize methyl chloride from reacting sodium chloride with dimethyl sulfate?

Metacelsus - 17-3-2019 at 10:45

I've never done it but it should be possible. Methyl chloride can be separated from the mixture (it's a gas) to drive the equilibrium forward.

Is there a reason you want to do this?

6dthjd1 - 24-3-2019 at 09:37

Yes, to make methylphosphonus dichloride from dissolving methyl chloride in tetrachloroethane mixed with aluminum trichloride and phosphorus trichloride

Metacelsus - 24-3-2019 at 10:27

Sounds like someone wants to make nerve gas . . .

But seriously, it's best if you stay away from that. Even if you're not trying to make chemical weapons, having the precursors can get you in quite a bit of trouble. (And methyl phosphonous dichloride is itself quite nasty.)

6dthjd1 - 24-3-2019 at 10:53

Laws vary. Ohio and Indiana can be quite tough, for instance, just see the definition of manufacture in 2925.04 ORC. It practically could be used to ban HCl gas synthesis.

Methylphosphonus dichloride is quite possibly an amenable route to nerve gases. However, some may contend it's an arduous process and other techniques are easier, if not nearly imperceptibly safer than the dichloromethylphosphine route, if one wanted nerve gases. Considering its potentially pyrophoric.

It's quite rare, sigma-Aldrich sells 10 ml for about $450.

Phosphorus trichloride itself is quite vicious to work with in my experience. Do you believe dichloromethylphosphine behaves similarly. It's more toxic than the trichloride but I believe it just as volatile as the trichloride. I do believe it's odor is more pronounced, however.

6dthjd1 - 6-4-2019 at 14:33

Some observations on the purported reaction of Dimethyl sulfate with sodium chloride:

A few grains of sodium chloride as sea salt was added to a few milliliters of dimethyl sulfate in a 250 ml round bottom boiling flask. The mixture was swirled to ensure even saturation of NaCl. The flask was subject to a mostly yellow flame of a Bunsen burner until effervescence was observed. The height of the flame was lowered to ensure less evaporation of dimethyl sulfate. A match was placed near the top of the flask to observe if ignition occurred. No ignition was observed.

Several days later
A visible excess of dimethyl sulfate of approximately 10 ml was placed in a 250 ml round bottom flask. A few grams of sodium chloride was added to the dimethyl sulfate. Some swirling commenced to ensure even saturation of the NaCl. A balloon was placed on the head of the flask to observe any gas collection. The balloon was deflated. The next day in the evening the balloon was inflated somewhat but not severely.

At this point the reaction of Dimethyl sulfate with sodium chloride may not be an amenable reaction for the synthesis of methyl chloride. Its presence in this reaction is doubtful because were it present it would have inflamed. I will consider igniting the balloon but am aware the dimethyl sulfate vapors are also inflammable albeit less flammable than the methyl chloride vapors.

SWIM - 7-4-2019 at 08:46

Seems like it ought to me possible to make it from methyl alcohol with HCl, ZnCl, or some other combo like that.
Sure works for ethyl chloride.

Not that I don't appreciate a flask of boiling dimethylsulfate as well as the next person.

6dthjd1 - 7-4-2019 at 14:24

I should note that this best be done at a minimum outdoors which is where I performed it. Doing this inside may not be imminently harmful but it is likely as safe as Russian roulette. During the early to mid 19th century, it seems that the chemists working with dimethyl sulfate lived... luckily.

wakatutu - 7-4-2019 at 17:20

Methyl Chloride unto itself is a nasty beast. It has all the same symptoms as methyl bromide and methyl iodide poisoning.

I made it by the accidental reduction of dichloromethane with HCl and copper salts. You might be able to do zinc, iron, copper, aluminum, etc. I don't know of any papers detailing the reduction but it should be completely possible. Chloromethane is unsurprisingly quite soluble in DCM so it might stick around rather than volatizing, making itself available for further reduction to methane, but I don't know.

6dthjd1 - 7-4-2019 at 17:29

How did your accidental reduction go?

wakatutu - 9-4-2019 at 00:18
a detailed report on the accidental reduction, and subsequent formation of a solid idea of what had happened.
my attempt to spark discussion on why the reduction took place