Chemistry: Acetaminophen (paracetamol) > Phenacetin

  • Thread starter tsuwal
  • Start date
  • Tags
    Chemistry
In summary, the question asks about the change in reaction velocity when using 2-iodopropane instead of ethyl iodide in a nucleophilic substitution reaction to convert acetaminophen to phenacetin. After considering the structures and steps of the reaction, it is determined that the change in rate may be due to the difference in substrate structure, specifically stereochemical repulsion, rather than the strength of the nucleophile.
  • #1
tsuwal
105
0

Homework Statement



To convert acetaminophen to phenacetin it was added NaOH in ethanol and then Ethyl iodide.
(Nucleophilic substitution). What would be the change in reaction velocity if insted of Ethyl iodide it was added 2-iodopropane (Isopropyl iodide)


Homework Equations





The Attempt at a Solution



what affects the velocity of the reaction? Is it the stability of the reaction of NaOH with Acetaminophen? If it is, then the velocity is the same although I'm not sure..
 
Physics news on Phys.org
  • #2
By velocity, the question asks to compare the rate of the two reactions. What do you think which nucleophilic substitution reaction takes place here? SN1 or SN2?
 
  • #3
SN1 in both, right? what do i Do next?
 
  • #4
tsuwal said:
SN1 in both, right? what do i Do next?

Nope, think again.
 
  • #5
with Ethyl iodide the reaction is SN1 because the reaction is given in two steps: first neutralization and then nucleophic substitution.
with 2-iodopropane i thought it was the same. is it as strong as Ethyl iodide as a nucleophyle?
 
  • #6
tsuwal said:
with Ethyl iodide the reaction is SN1 because the reaction is given in two steps: first neutralization and then nucleophic substitution.
with 2-iodopropane i thought it was the same. is it as strong as Ethyl iodide as a nucleophyle?

Check the structure of acetaminophen. What happens when NaOH is added to it? (Hint: There is an acidic hydrogen)
 
  • #7
the hydrogen of the hydroxyl group neutralizes the OH- from NaOH to form water. The oxygen in acetaminophen becomes negative and a good nuclephyle and attacks the iodine in Ethyl iodide or 2-iodopropane. Now that I think of, it is a SN2 reaction, at least with ethyl iodine. What next?
 
  • #8
tsuwal said:
the hydrogen of the hydroxyl group neutralizes the OH- from NaOH to form water. The oxygen in acetaminophen becomes negative and a good nuclephyle and attacks the iodine in Ethyl iodide or 2-iodopropane. Now that I think of, it is a SN2 reaction, at least with ethyl iodine. What next?

Yes, you have that right. Now what happens when you use secondary alkyl halide instead of a primary one? Does the rate increase or decrease?
 
  • #9
the rate of a SN2 reaction depends on how stong the nucleophyl is, right? does it depend on the substrate, eletrophyl? Well, if it depends on the eletrophyl, with 2-iodopropane there is more stereochemical repulsion, so, is it slower with 2-iodopropane?
 
  • #10
tsuwal said:
the rate of a SN2 reaction depends on how stong the nucleophyl is, right? does it depend on the substrate, eletrophyl? Well, if it depends on the eletrophyl, with 2-iodopropane there is more stereochemical repulsion, so, is it slower with 2-iodopropane?

Haven't you yet completed this topic? The rate depends on the substrate, the leaving group and the attacking nucleophile. It should be in your text about the rate dependence on the structure of substrate. We have the same leaving group and the attacking nucleophile in both the cases so we need not bother about that.
 

What is acetaminophen?

Acetaminophen, also known as paracetamol, is a commonly used medication for pain and fever relief. It is a white, crystalline compound and is often found in over-the-counter medications such as Tylenol.

What is phenacetin?

Phenacetin is a compound that was previously used as a pain reliever and fever reducer, but has been banned in many countries due to its potential to cause kidney damage and cancer. It is a white, crystalline powder and is similar in structure to acetaminophen.

How are acetaminophen and phenacetin related?

Acetaminophen and phenacetin are both analgesic and antipyretic compounds, meaning they can relieve pain and reduce fever. They are also similar in chemical structure and share a common intermediate in their synthesis pathway.

Why was phenacetin banned?

Phenacetin was banned in many countries due to its potential to cause kidney damage and cancer. It was found to be toxic to the kidneys and could lead to a condition called nephropathy, which can be fatal. It was also classified as a possible carcinogen by the International Agency for Research on Cancer.

What are the potential side effects of acetaminophen and phenacetin?

The potential side effects of acetaminophen include liver damage, especially when taken in high doses. Phenacetin, on the other hand, can cause kidney damage and cancer. Both compounds can also cause allergic reactions in some individuals.

Similar threads

  • Biology and Chemistry Homework Help
Replies
1
Views
3K
  • Biology and Chemistry Homework Help
Replies
4
Views
7K
  • Biology and Chemistry Homework Help
Replies
1
Views
4K
  • Biology and Chemistry Homework Help
Replies
4
Views
1K
  • Biology and Chemistry Homework Help
Replies
16
Views
3K
  • Biology and Chemistry Homework Help
Replies
1
Views
5K
  • Biology and Chemistry Homework Help
Replies
1
Views
2K
  • Biology and Chemistry Homework Help
Replies
1
Views
1K
  • Biology and Chemistry Homework Help
Replies
4
Views
2K
  • Biology and Chemistry Homework Help
Replies
1
Views
2K
Back
Top