Purpose of ether in Grignard reagent preparation

  • Thread starter Thread starter skierboy
  • Start date Start date
  • Tags Tags
    Ether Preparation
Click For Summary

Discussion Overview

The discussion revolves around the role of ether in the preparation of Grignard reagents, specifically in the context of a reaction involving bromobenzene, magnesium metal, and anhydrous ether. Participants explore the implications of omitting ether during the reaction process and its effects on the formation and stability of the Grignard reagent.

Discussion Character

  • Homework-related
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant suggests that without ether, the Grignard reagent would precipitate and remain as a solid, implying that ether is necessary to keep the reagent in a liquid phase.
  • Another participant clarifies that the Grignard reagent does not survive in aqueous conditions, indicating the importance of maintaining a non-aqueous environment.
  • A question is posed regarding the effects of adding more ether to the reaction mixture, assuming the product does not precipitate, suggesting that ether plays a role in facilitating the reaction.
  • It is noted that ether acts as a coordinating solvent that associates with magnesium salts, and adding more solvent would dilute the reaction mixture.
  • Participants inquire about the nature of the reaction, questioning whether it is vigorous and the implications of ether being a low-boiling solvent.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of ether for the formation of the Grignard reagent and its role in the reaction. The discussion remains unresolved regarding the specific consequences of omitting ether.

Contextual Notes

There are assumptions regarding the behavior of the Grignard reagent in the absence of ether, and the discussion does not clarify the exact conditions under which the reaction occurs or the potential outcomes of leaving ether out.

skierboy
Messages
10
Reaction score
0

Homework Statement



Regarding the preparation of benzoic acid via a Grignard reagent:

*Initial bromobenzene solution includes bromobenzene, magnesium metal and anhydrous ether.

Once the initial bromobenzene/Mg solution undergoes boiling, you forget to add additional anhydrous ether to the reaction mixture - what happens? 2. The attempt at a solution

I believe that the Grignard reagent would precipitate without the presence of ether - all of the Grignard reagent would be formed, but it would ultimately be all solid. That is, the ether keeps the Grignard reagent in an aqueous phase. Is this correct?

Thanks in advance!
 
Physics news on Phys.org
skierboy said:
the ether keeps the Grignard reagent in an aqueous phase. Is this correct?

In LIQUID phase.

Not that I know anything else, but Grignard doesn't survive aqueous.
 
Your initial conditions show that your reaction pot contains ether as well as Mg and bromobenzene. Assuming that the ether doesn't boil away, adding additional ether will do what?

Hint: Assume that your product doesn't precipitate.
 
The ether facilitates the reaction? So, essentially, the presence of ether allows for the formation of the Grignard reagent? Without ether, it wouldn't form...?
 
No, the ether is the solvent. It is a coordinating solvent so it accociates with magnesium salts (like the Grignard). When you add more solvent you dilute the reaction mixture.

So, what would happen if you left it out? What is the next step? Is it a particularly vigorous reaction? (remember that ether is a very low-boiling solvent)
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
1
Views
11K
Replies
9
Views
5K
  • · Replies 2 ·
Replies
2
Views
12K
  • · Replies 19 ·
Replies
19
Views
10K
  • · Replies 266 ·
9
Replies
266
Views
32K
  • · Replies 2 ·
Replies
2
Views
10K