[Bunsen Honeydew]

It seems that trimethylsilyldiazomethane is no longer available. I called Aldrich and all they could tell me was it was a government regulation. Anyone know anything about this?

[Mitch]

It seems rather hazardous. But I didn't know it got banned.

http://pipeline.corante.com/archives/2009/01/23/the_real_hazards_of_the_lab.php

[Bunsen Honeydew]

Hi Mitch. Yeah, I remember that whole mess. I tried hunting around online for some sort of notice but got nothing. I am an academic in Canada and we can't even get diazald here anymore. I have a glassware kit for it but I guess I may have to make my own. The issue that arises from that is that you use methylamine. Breaking Bad flashbacks, anyone? Yeah, good luck getting that. You can buy small amounts of the hydrochloride but then you have to free base it in situ. Fun fun fun.

[wisconsinium]

I am not sure it is related, but this reminded me of a C&EN article from last year. This guy should have survived if the fume hoods were working in the first place though..

Chem. Eng. News, 2011, 89 (19), p 15

"DRUGMAKER SEPRACOR CANADA pleaded guilty in a Canadian court on May 2 to one charge of failing to provide proper workplace ventilation and will pay a U.S.$47,000 fine for the death of chemist Roland Daigle.

Daigle died on Oct. 8, 2008, from lung failure after exposure to trimethylsilyldiazomethane (TMSD) in a quality control laboratory at the company’s Windsor, Nova Scotia, facility.

The plea and fine were part of a deal in which the prosecutor dropped four other charges against the company, a subsidiary of Sunovion Pharmaceuticals. The other charges involved hazardous material training, use of personal protective equipment, and maintaining the security of the accident scene.

The day before he died, Daigle, 46, worked with TMSD, (CH 3 ) 3 SiCHN 2 , when lab fume hoods were not operating because of roof work. TMSD can be used as a methylating reagent in place of diazomethane, which is explosive..."

[OC pro]

I have read the report http://informahealthcare.com/doi/pdf/10.1080/15563650903076924
He mixed 2ml acetone and 25ml malic acid with TMS-Diazomethane and came to death because the fume hood was not working properly? I can hardly believe it. I had more serious stuff in my lab days (liters) and never had anything.

Here in Europe the hexane solution of TMS-Diazomethane is freely available.

[discodermolide]

I have read the report http://informahealthcare.com/doi/pdf/10.1080/15563650903076924
He mixed 2ml acetone and 25ml malic acid with TMS-Diazomethane and came to death because the fume hood was not working properly? I can hardly believe it. I had more serious stuff in my lab days (liters) and never had anything.

Here in Europe the hexane solution of TMS-Diazomethane is freely available.

I think a lot of these reports are due to some creative poetic journalistic thing. TMS-diazomethane is certainly dangerous when ingested or inhaled in quantity, I do not know if it works transdermally, but working with it under lab conditions with normal quantities used in a lab, I do not think it is a problem.
As you said OC, there are a lot worse to be found in the normal lab.

[Borek]

The report in question comes from the 2009 North American Congress of Clinical Toxicology Annual Meeting, so at least it is not an exaggerated and uniformed journalism. See page 712, abstract 48:

Case report: A 46 year-old
male pharmaceutical chemist presented to the ED with
progressive dyspnea. At noon on the prior day, as part
of a chemical analysis, he had mixed 2 mL of acetone
with 25 mL of L-Malic acid to which was added TSDM
dissolved in n-hexane. After 1 hour this mix was combined
with an inert gas and a small amount of methylene
chloride under a fume hood that was later reported to be
nonfunctioning. Although he experienced no immediate
mucous membrane irritation, 8 hours post-exposure he
developed cough, pleuritic chest pain, hemoptysis, and
progressive shortness of breath; by 15 hours, he presented
to the ED in respiratory distress, hypoxic (PaO2
67), hypercarbic (PaCO2 46), and acidemic (pH 7.26).
A chest radiograph showed an acute lung injury pattern.
By 23 hours he required intubation. At 26 hours postexposure
he developed profound bradycardia, refractory
hypotension, and asystole.

Judging from the discussion they have no idea what exactly triggered the symptoms.

[discodermolide]

Crucially they do not say how much TMS-diazomethane was being used. Information which would be extremely relevant and nice to know.

[nox]

I wonder how the hazards of methyl triflate compare with TMS-diazomethane. Had to run a reaction using 10g of methyl triflate and it was probably the most unnerving day of my life, but after reading the report I wonder whether I might've overreacted a bit.

[OC pro]

Not worse/better than iodomethane or dimethylsulphate. Using a proper working fume hood and gloves no prob at all.
People always mix Magic methyl (methyl fluorosulphonate) with methyl triflate (which is far less toxic). There were several reported deaths in the group which has invented it.

[nox]

^No I didn't mix them up. Magic Methyl is banned and is no longer commercial anyway. It's just that I read somewhere methyl triflate is orders of magnitude more reactive than methyl iodide, plus it's a really really hard electrophile which means it'll O-alkylate the DNA bases with ease.

[curiouscat]

Who bans these things? OSHA? EPA? Who has the authority for this sort of thing I was wondering.

[discodermolide]

Who bans these things? OSHA? EPA? Who has the authority for this sort of thing I was wondering.

I think you will find that it is the suppliers themselves who "ban" these compounds, working together with the appropriate authority. Especially if there has been an incident with one of them.

[rmflores]

It is available on aldrich again. I wonder if at some point it won't be available again since all they could say was that it had regulation issues. Now they say the only thing they know is that it is available now.. How can one develop a method with a chemical that might not be offered in the near future..

[discodermolide]

This is of course difficult. You could buy their entire supply. Or select a different reagent that does the same thing. I don't know how far you've come with TMSdiazomethane in your development, but it may be wise to buy as much as you can while it is available again.