Synthesis of Phenylacetic acid from Mandelic acid (small scale)

[WillD]

Reaction scheme:

Synthesis:
1. Mandelic acid (15,0 g) was dissolved in hypophosphorous acid 85% aq (15 ml).

2. Iodine (15 g) was added in a small portions, whilst heating at reflux for 1 hour.

3. The solution was poured over cold water and the crude product recrystallised from hot water to yield a colourless crystalline product 10 g.

 

[rabbitass]

Hello, I am very interested in this synthesis, at least where I am from it is very easy to get kg of L-mandelic acid, what I am having a hard time is getting the hypophosphorous acid, can I replace it with another acid that is easier for me to get?

 

[lalalander]

Hello, I am very interested in this synthesis, at least where I am from it is very easy to get kg of L-mandelic acid, what I am having a hard time is getting the hypophosphorous acid, can I replace it with another acid that is easier for me to get?

rabbitassI don't think so. If you can find red phosphorus, you can also use phosphoric acid. It is much, much easier to find than hypophosphoric acid. Of course, finding red phosphorus is still a problem.

 

[lalalander]

Hypophosphorus acid is a pain in the ass to find.

 

[WillD]

It is precisely hypo. It is hard to get, but it suits the best. Obtaining meth from ephedrine is similar.

 

[hacke8]

It is precisely hypo. It is hard to get, but it suits the best. Obtaining meth from ephedrine is similar.

WillDHello, Will Chemist, can you publish a thread for preparing P2P with phenylacetic acid? I haven't found it for a long time. Thank you.