[zsinger]

All,
Is it ok to EVER have an alkyl diazonium if it is kept VERY cold and in a large XS of water in order to make a Sandmeyer happen in situ?  Are these alkyl-diazoniums too unstable to work with?
              -Zack

[phth]

whats the counter ion? I think only things which are really unstable cations are ok.  For example, Ph-N₂F cation orthogonal to the ring; diazomethane is another example of unstable cation.  It may be a stable salt with a counter ion like SbF₆, but I'm not sure. 

[C-hemCards]

There are some examples out there, particularly on amino acid substrates. I'm 99% sure there is an industrial process that does this on an amino acid. Be careful though, sometimes diazo salts can blow up on you. Keep the scales small until you know how it behaves.

[phth]

Interesting response chem cards. Reference? Some dude thought it would be okay to add NaNO2 to an alkyl amine: they leveled an entire fertilizer plant. Ibid: be careful. Also, what a shameless advertising plug chem cards. Is native advertising okay like this mods? Cuz this is the first example I have seen on this forum.

[C-hemCards]

I don't know the references off the top of my head, but know where they are at in my office (where I am not for the next few days). In principle, any diazonium salt is stable, but accidents happen when there is a trigger for ignition. Sometimes that can be metal impurities in the reagents added to the reaction mixture. In the lab environment, it's usually an impact shock, most often when the diazonium salt gets trapped in a ground glass joints. The most frequent occurrence of this is rotovaping a solution of these compounds. Definitely be careful, but it can be done safely if important enough.

I hope my plug for the cards is not too much. We think that they are a great resource, and a badly needed one at that. After more than a year in design and development, we are excited to have them out there.

[Arkcon]

Also, what a shameless advertising plug chem cards. Is native advertising okay like this mods? Cuz this is the first example I have seen on this forum.

The posting on the topic is in free advertisements, and a tagline in the sig field is OK, so long as the poster makes quality posts.

Interesting response chem cards. Reference? Some dude thought it would be okay to add NaNO2 to an alkyl amine: they leveled an entire fertilizer plant. Ibid: be careful.

Actually, since you've brought up this story, I'd like to see its reference cited.  What fertilizer plant, why were they doing sloppy organic chem, etc.

[discodermolide]

I don't know the references off the top of my head, but know where they are at in my office (where I am not for the next few days). In principle, any diazonium salt is stable, but accidents happen when there is a trigger for ignition. Sometimes that can be metal impurities in the reagents added to the reaction mixture. In the lab environment, it's usually an impact shock, most often when the diazonium salt gets trapped in a ground glass joints. The most frequent occurrence of this is rotovaping a solution of these compounds. Definitely be careful, but it can be done safely if important enough.

I hope my plug for the cards is not too much. We think that they are a great resource, and a badly needed one at that. After more than a year in design and development, we are excited to have them out there.

Are you not confusing a diazonium salt with diazomethane? The latter is very unstable and can explode, especially using ground glass joints or to shock, when it is concentrated enough.

[C-hemCards]

You're absolutely correct about diazomethane; that one is dangerous and there is little need to make it anymore given the commercial availability of TMSCHN2. However, the same precautions should be taken with dizaonium salts, regardless of counterion. More generally, serious precautions should be taken with any diazo compound and any compound that is approaching a low ratio of carbon:nitrogen, regardless of structure. One has to use their own judgement (in the absence of DSC analysis) as to what could be dangerous, but if you've thought twice about a compound, it's best to treat it with care.

[Dan]

Alkyl diazo compounds that are stabilised by electron withdrawing groups are ok to work with.

Examples are α-diazocarbonyls (such as those generated from diazotisation of amino acid derivatives [example]), and diaryldiazomethanes.

Highly stabilised diazos, like diazomalonates, can be chromatographed on silica, recrystallised from hot protic solvents etc.

Diazo Meldrum's acid can even be melted (~100 °C) without decomposition.

I would just point out that these are not diazonium salts, they are (neutral) diazo compounds. I am not aware of any isolable alkyldiazonium salts.

[C-hemCards]

Interesting, Dan, thank you. I did not know that some diazo compounds could be chromatographed/melted(!)

[zsinger]

No, I was speaking of a compound such as amino 2 propanone (Acetone with a NH2 instead of a CH3 on one side --> naming was never my forte!)
           -Zack

[Dan]

No, I was speaking of a compound such as amino 2 propanone (Acetone with a NH2 instead of a CH3 on one side --> naming was never my forte!)

You mean diazoacetone? This one?

That is an α-diazocarbonyl - I did mention these.

If you don't know how to name something, at least draw it. You can get a chemical structure drawing program to name things for you, or there are some free websites, like chemicalize.org, that will do structure name. We all need to be speaking the same language, that is the point of nomenclature.

[discodermolide]

"Acetone with a NH2 instead of a CH3 on one side"

This is acetamide.

[zsinger]

Findings:
Acetamide CAN successfully have a "OH" substitution, if kept cold!  Organic Chemistry is an experimental science!  Confirmed by H-NMR spec.