Grignard with benzoic acid

[tareek]

How do 2 equivalents Grignard react with benzoic acid. The first one will deprotonate the acid proton. But will the second one attack the carboxylat ?

By the way we are using a weak acid 

[chenbeier]

Carbonic acids cannot be treated with Grignard

https://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Grignard_with_carbonyl.png/450px-Grignard_with_carbonyl.png

You can see they also treated CO2 to make carbonic acid. This would be not possible if carbonic acid would under go Grignard.

Edited March 2 by chenbeier

[exchemist]

1 hour ago, tareek said:

How do 2 equivalents Grignard react with benzoic acid. The first one will deprotonate the acid proton. But will the second one attack the carboxylat ?

By the way we are using a weak acid 

Carboxylate anions are not very strongly electrophilic, if I remember correctly. What do you think will happen?

2 minutes ago, chenbeier said:

Carbonic acids cannot be treated with Grignard

data:image/png;base64,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

 

Something has gone wrong with your post.

Edited March 2 by exchemist

[tareek]

1 hour ago, exchemist said:

Carboxylate anions are not very strongly electrophilic, if I remember correctly. What do you think will happen?

Something has gone wrong with your post.

I dont know i would say the benzoic acid, will be formed back. But are you sure Acetophenon can't forn

[chenbeier]

If so why should it stop at acetophenon, this could react to 2 Phenyl-2-propanol. But it doesn't happen. If you use instead of the acid the ester then its possible.

 

Edited March 2 by chenbeier

[tareek]

Because we only have 2 equivalents of Grignard

[chenbeier]

Why do you think it will not stop.

If it works it will go through, even you have only two equivalent. Then some reactant will be left.

 

Edited March 2 by chenbeier

[exchemist]

33 minutes ago, tareek said:

I dont know i would say the benzoic acid, will be formed back. But are you sure Acetophenon can't forn

The problem, as @chenbeier says,  is that a carbonyl group will react with a Grignard reagent much faster than a carboxylate. So any acetophenone produced would immediately react in preference to the remaining carboxylate. I’m not sure whether a carboxylate anion will react at all with a Grignard reagent. Nucleophilic attack on an anion seems like a bit of an uphill struggle, though it’s true most of the -ve charge will be on the O atoms.