[mimi.janson]

I am new here and firstly i want to say sorry if i was not sure about how to ask a question before, but i will try to make myself more clear this time, but please do not be too harsh since English is not my first language.

So i am doing a big project about a reaction between 4-aminophenol and acetic acidhydrate which will create paracetamol and acetic acid. But i need to know where the NH₂ gets its H⁺ from since it has a lonepair and needs to get a H⁺ for the reaction to happen?

I have already done research and sometimes i find information that says that the H⁺ comes from the acetic anhydrite and sometimes i read that one has to add water before the reaction can even begin. So is it right i would need water?

I hope i did not break any rules with this post, since i was shocked how many rules i could actually break with the first one, so please remember Im new here

[discodermolide]

Amines are nucleophiles. Are protonated amines, i.e. NH₃⁺ nucleophillic?

p.s. Water may not be good for this reaction as it will hydrolyse the acetic anhydride.

[orgopete]

I looked at the reaction in your first post. It did not and does not need water. All of the required atoms are present in the raectants. Water may be used as a solvent or in the isolation of the product, but that is a different question.

[mimi.janson]

when you say all the required atoms are present it gives a lot of since, because i tried to put a picture i had drawn of the reaction, and the water basically just went in and out not being used.

But what do you mean with that the water may be used as a solvent or in the isolation of the product? Could you explain that to me, because i think it is important.

Besides i have a picture i want to add to this post do you know how? I want to show what i know in the drawing

[mimi.janson]

Amines are nucleophilic. Are protonated amines, i.e. NH₃⁺ nucleophillic?

p.s. Water may not be good for this reaction as it will hydrolyse the acetic anhydride.

well i was told to use a book where it is written what is and what is not nucleophillic, and there is written that it can for example be NH₃, H₂O,OH^-,  there are no ones with a ⁺ but only ones with ^-

[discodermolide]

Well that is your answer. No water.

[curiouscat]

Besides i have a picture i want to add to this post do you know how? I want to show what i know in the drawing

Look up in the toolbar. 2nd row from top, 2nd icon from left.

[orgopete]

But what do you mean with that the water may be used as a solvent or in the isolation of the product? Could you explain that to me, because i think it is important.

It is important to draw a distinction between stoichiometry and the mechanism. If water atoms were quieted to complete formation of the product, then it would be required. If an excess of reagents improves the formation of the product, it still isn't required. If acetic anhydride contained 10% acetic acid, the reaction can still be completed by just compensating for the apparent lack of anhydride. After all, acetic acid is a by-product of the acylation and therefore should not interfere with formation of the product. This latter point is really about stoichiometry. If the aniline reacted 100 times faster than water, then the reaction could be run in water provided one compensated for a slow competing reaction of the anhydride with water.

This brings us to two facets of this reaction. Water is a cheap solvent with many desireable properties for this reaction and acetic anhydride is cheap. If water does react and I expect that it does, will it matter? The second facet is which atom is more nucleophilic, a nitrogen or an oxygen? Granted that is quite a large generalization as an aniline is not a general nitrogen, but one should have some idea about why atoms might be nucleophilic and how that might affect an aniline.