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Topic: Help with diazonium and azide chemistry protocol  (Read 7647 times)

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Offline asdfTT123

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Re: Help with diazonium and azide chemistry protocol
« Reply #15 on: May 08, 2013, 11:28:57 AM »
So do you guys think there is a possibility that I formed an azo dye?  When I had initially added the amine to the HCl, it went into solution (protocol stated it was a slurry), and when I added the sodium nitrite solution, I saw a yellow-ish precipitate, while the protocol said the turned into a clear solution.

I'm pretty confused because I followed the protocol exactly except all reagents were halved.

Had the azo dye formed from the first step, I'm guessing there was no reaction at all with the sodium azide?

Offline opsomath

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Re: Help with diazonium and azide chemistry protocol
« Reply #16 on: May 08, 2013, 11:33:04 AM »
Nah. Don't worry too much about the visual cues from the paper. There's no way you formed an azo dye that cleanly, and they're usually a very bright color anyhow. I would place good money that your reaction worked perfectly. NMR with IR will tell you more.

Offline asdfTT123

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Re: Help with diazonium and azide chemistry protocol
« Reply #17 on: May 08, 2013, 11:40:25 AM »
Thank you for the help, opsomath.

Just out of curiosity, what types of manipulations or adjustments can be changed to the diazotization protocol to ensure limited azo dye production and maximum synthesis of the desired diazonium ion?

For someone who's more interested in synthesizing an azo dye, what can be done to limit the diazonium product and maximize the azo product?

Does adding the sodium nitrite solution to amine/HCl or vice versa really have any effect either way around?   How about limiting the concentration of the amine in HCl?

Also, even if my reaction does work, would I expect to see a mixture of azo dye and my desired azide compound in my extracted EtOAc fraction?  I'm wondering because I only see a major spot at around Rf 0.6 in 1:5 EtOAc:Hexanes a very faint spot at the starting location.

I'm trying to figure out what are the potential side products from this reaction and why the authors of this paper ran a column.

Many thanks.

Offline opsomath

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Re: Help with diazonium and azide chemistry protocol
« Reply #18 on: May 08, 2013, 01:55:21 PM »
My advice to you would be not to overthink this. If the conditions aren't leading to azobenzene formation, don't change them. If TLC doesn't show that you need a column, don't run one; recrystallize, or do a plug column.

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