Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Synthesizing Nitrobenzene [Video]
thors.lab
Hazard to Others
***




Posts: 103
Registered: 19-7-2019
Member Is Offline


[*] 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.
View user's profile Visit user's homepage View All Posts By User
Ynzept
Harmless
*




Posts: 2
Registered: 26-8-2019
Member Is Offline


[*] 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




View user's profile View All Posts By User
Herr Haber
International Hazard
*****




Posts: 1236
Registered: 29-1-2016
Member Is Offline

Mood: No Mood

[*] 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
View user's profile View All Posts By User
thors.lab
Hazard to Others
***




Posts: 103
Registered: 19-7-2019
Member Is Offline


[*] 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.
View user's profile Visit user's homepage View All Posts By User
Cactuar
Harmless
*




Posts: 32
Registered: 25-7-2014
Location: Denmark
Member Is Offline

Mood: No Mood

[*] 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.
View user's profile View All Posts By User
thors.lab
Hazard to Others
***




Posts: 103
Registered: 19-7-2019
Member Is Offline


[*] 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.
View user's profile Visit user's homepage View All Posts By User
DavidJR
National Hazard
****




Posts: 908
Registered: 1-1-2018
Location: Scotland
Member Is Offline

Mood: Tired

[*] 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.
View user's profile View All Posts By User
monolithic
Hazard to Others
***




Posts: 435
Registered: 5-3-2018
Member Is Offline

Mood: No Mood

[*] posted on 27-8-2019 at 17:50


Nice job. I really enjoy the cost analysis at the end of your videos.
View user's profile View All Posts By User
icelake
Harmless
*




Posts: 48
Registered: 9-10-2017
Member Is Offline

Mood: No Mood

[*] 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...
View user's profile View All Posts By User
thors.lab
Hazard to Others
***




Posts: 103
Registered: 19-7-2019
Member Is Offline


[*] 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.
View user's profile Visit user's homepage View All Posts By User

  Go To Top