ScienceHideout
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4-Nitroaniline
Hello everyone. I want to synthesise p-nitroaniline (or 4-nitroaniline) for an experiment to make carbon. I would like a few grams, at the least. Does
anyone know how I could go about doing this? Thank you.
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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mario840
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You must start from aniline, NH2 group is very strong activator ring so if you nitrate that (aniline) you get orto, para position with NO2 , so must
make "least" activate, aniline + acetic anhydride you will get acetanilide (amide) so then you nitrate this with HNO3/H2SO4 to get 2 products
2-nitroaniline and 4-nitroaniline, you will separate them by destillation etc.
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ScienceHideout
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Sounds like a good weekend project! I will definately do a bit more research
based on what you just told me and make this. Thanks a mole!
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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mario840
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Also i forget adding when you finally nitrate this amide , last step is making amide group back to amine this is simple .... hydrolysis with NaOH +
H2O will do the job
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entropy51
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Or you could have
done a tiny bit of research before posting. Several books in the forum library describe this synthesis.
I have to agree with Nicodem: Quote: Originally posted by Nicodem | Posting ideas without showing knowledge is fully acceptable, but posting ideas without investing even one minute of literature search into it (and not
even comparing molecular structures!), is not scientific at all. | And you propose to set up a sub-forum for
research?
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Mildronate
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Funny i had 1kg botlle of it, good stuf to make diasoinum perchlorate from it
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Jor
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Quote: Originally posted by mario840 | Also i forget adding when you finally nitrate this amide , last step is making amide group back to amine this is simple .... hydrolysis with NaOH +
H2O will do the job |
AFAIK this won't be a good idea as the nitro-group is strongly electron withdrawing, treating the amide with conc. NaOH might convert a great deal off
the amine to phenol. I would use hydrochloric acid instead. I remember I read this somewhere.
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smuv
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haha! the wiki even tells you how to synthesize it.
http://en.wikipedia.org/wiki/4-Nitroaniline
Edit: found a good ref. I might just go for nitration of aniline and seperate the isomers. When it comes to nitration of acetanilide, i found two
refs that indicate better selectivity for para (>99%) when NaNO3/H2SO4 is used as the nitrating agent (as opposed to mixed acids). I assume this
is due to lower NO2+ concentrations???
Attachment: nitration_anilines_carbamates_acetanilides.pdf (775kB) This file has been downloaded 1124 times
[Edited on 6-25-2011 by smuv]
"Titanium tetrachloride…You sly temptress." --Walter Bishop
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entropy51
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From a llink on the Wiki page cited by smuv
Quote: | Experimental
Acetanilide: Measure 5.0 g of aniline into a 125-mL Erlenmeyer flask. Add 40 mL of water to the flask. Stir the contents while adding 6.5 mL of acetic
anhydride. After the addition, stir for an additional 10 min and then vacuum filter the product. Spread the solid out on a large piece of filter paper
in a petrie dish to dry quickly. Save a little for characterization and use the rest in the next step.
p-Nitroacetanilide: Add 3.0 g of acetanilide to 5 mL glacial acetic acid in a 25-mL Erlenmeyer flask. Carefully pour 5 mL concentrated sulfuric acid
into the mixture while stirring constantly. After the acetanilide has dissolved, place the flask in an ice-salt bath and cool it to 5 ºC. Prepare a
solution of 2 mL concentrated nitric acid and 1.3 mL concentrated sulfuric acid. While stirring the acetanilide solution, add dropwise the
nitric/sulfuric mixture at a rate such that the temperature does not rise over 20 ºC. After the addition, let the mixture stand at room temperature
for 20 min. Pour the reaction mixture into 25 mL of cold water with 15 g of ice. Collect the solid that forms by vacuum filtration and wash the solid
with three 30-mL portions of cold water. Recrystallize the solid from 95% ethanol and characterize it.
p-Nitroaniline: Add 2.2 g of p-nitroacetanilide and 5 mL of water to a 25 mL round bottom flask. Slowly add 5 mL concentrated sulfuric acid while
swirling. Reflux the mixture for 30 min. Cool the reaction mixture and pour the contents into a mixture of 15 g ice in 20 mL water. Slowly with
stirring add 9 M sodium hydroxide until the pH of the mixture reaches 4-5. Cool the mixture in an ice bath and collect the precipitate by vacuum
filtration. Wash the solid four times with 20 mL portions of water. Characterize the p-nitroaniline. |
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