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Author: Subject: Synthesizing Nitrobenzene [Video]
thors.lab
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[*] posted on 26-8-2019 at 22:21
Synthesizing Nitrobenzene [Video]


Hi,

I've made a new video on the synthesis of nitrobenzene. As always, please check my signature for the link to the video.

Please let me know of any improvements I could have made to the procedure, video editing, narrating, and safety.

If anybody has any idea why the yield was relatively low (64%) please share.

I plan to make phenylhydroxylamine next, then p-aminophenol, then acetaminophen. However, this will have to wait as I've moved and didn't bring my lab equipment yet.

If you have suggestions for other videos, let me know!

Thanks,

Thor




Please check out my latest video: Synthesizing Nitrobenzene, and the last one:
Making Nitric Acid.
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Ynzept
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[*] posted on 26-8-2019 at 23:01


Quote: Originally posted by thors.lab  


If anybody has any idea why the yield was relatively low (64%) please share.

Thor


T. Davis: "The nitration of m-dinitrobenzen is too expensive of acid and heat for practical application, and the yields are poor. Toluene and chlorobenzene are nitrated more easily and more economically, [...]. "

So you could try chlorinating your benzene first or nitrate toluene, then oxidize by means of chromic acid in sulphuric acid solution.

Hope this helps




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Herr Haber
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[*] posted on 27-8-2019 at 03:44


I'm still waiting for someone to synthesize acetaminophen from willow bark or crude oil :)
Absolutely pointless of course but nowadays people snort cinnamon as a challenge...




The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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thors.lab
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[*] posted on 27-8-2019 at 07:42


Quote: Originally posted by Herr Haber  
I'm still waiting for someone to synthesize acetaminophen from willow bark or crude oil :)
Absolutely pointless of course but nowadays people snort cinnamon as a challenge...


I have most of it planned out besides the last step — i can’t figure out how to get my hands on acetic anhydride for p-aminophenol -> acetaminophen




Please check out my latest video: Synthesizing Nitrobenzene, and the last one:
Making Nitric Acid.
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Cactuar
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[*] posted on 27-8-2019 at 11:45


Instead of doing 2 water washes I would do one with saturated NaHCO3 and one with brine. This would minimize the amount of product dissolved in the aqueous phase and reduce the amount of drying agent needed. I would also dry the product before distillation. And looking at the product at 4:27 it looks like the MgSO4 is moving like a sludge at the bottom of the flask, this tells me it's not really dry. It should be like a hard cake with small amounts powdered MgSO4 swirling around freely and refusing to "aggregate" with the others.
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thors.lab
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[*] posted on 27-8-2019 at 11:54


Quote: Originally posted by Cactuar  
Instead of doing 2 water washes I would do one with saturated NaHCO3 and one with brine. This would minimize the amount of product dissolved in the aqueous phase and reduce the amount of drying agent needed. I would also dry the product before distillation. And looking at the product at 4:27 it looks like the MgSO4 is moving like a sludge at the bottom of the flask, this tells me it's not really dry. It should be like a hard cake with small amounts powdered MgSO4 swirling around freely and refusing to "aggregate" with the others.


These are great suggestions! Thank you!




Please check out my latest video: Synthesizing Nitrobenzene, and the last one:
Making Nitric Acid.
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DavidJR
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[*] posted on 27-8-2019 at 16:32


You used rather a lot of magnesium sulphate, which probably contributed to the yield. I'd use a smaller amount and add more if needed until the supernatant becomes clear.
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[*] posted on 27-8-2019 at 17:50


Nice job. I really enjoy the cost analysis at the end of your videos.
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icelake
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[*] posted on 28-8-2019 at 03:40


Quote: Originally posted by thors.lab  
I have most of it planned out besides the last step — i can’t figure out how to get my hands on acetic anhydride for p-aminophenol -> acetaminophen


Can you try this method?

https://archive.org/download/ChemPlayer/Acetic%20anhydride%2...
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thors.lab
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[*] posted on 28-8-2019 at 21:43


Quote: Originally posted by DavidJR  
You used rather a lot of magnesium sulphate, which probably contributed to the yield. I'd use a smaller amount and add more if needed until the supernatant becomes clear.


I tried to go little by little, I suppose I had a lot of water left because of the mistake during distillation. :/




Please check out my latest video: Synthesizing Nitrobenzene, and the last one:
Making Nitric Acid.
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