[Nescafe]

Hi,

Mostly I see people showing the synthesis of aspirin starting with salicylic acid which I've done myself. I rarely find new ways of synthesizing salicylic acid starting from benzene. Does anyone know of recent efficient ways of doing this?

Nescafé

[Arkcon]

Why not start with benzene, then consider the functional groups needed to reach salicylic acid, plan a number of synthetic steps?

[Nescafe]

Why not start with benzene, then consider the functional groups needed to reach salicylic acid, plan a number of synthetic steps?

cause Benzene is nasty?

[Arkcon]

Start on paper.  Then, you can plan the procedure around the appropriate lab hygiene measures for adequate safety.  You can also use Wikipedia -- the salicylic has to come from somewhere.  Industrially, its made from phenol and CO₂ under pressure.  http://en.wikipedia.org/wiki/Kolbe-Schmitt_reaction

[Nescafe]

Start on paper.  Then, you can plan the procedure around the appropriate lab hygiene measures for adequate safety.  You can also use Wikipedia -- the salicylic has to come from somewhere.  Industrially, its made from phenol and CO₂ under pressure.  http://en.wikipedia.org/wiki/Kolbe-Schmitt_reaction

I see, so phenol, apply pressure, bubble in CO2, electrophilic addition, acidify?

Nescafe.

[curiouscat]

I see, so phenol, apply pressure, bubble in CO2, electrophilic addition, acidify?

Don't know if you noticed the pressure at Wikipedia: P=100 atm

[Nescafe]

I see, so phenol, apply pressure, bubble in CO2, electrophilic addition, acidify?

Don't know if you noticed the pressure at Wikipedia: P=100 atm

Your point being that there's no need to bubble the CO2. Would this be an electrophilic addition?

[camptzak]

is the CO₂ in the liquid phase at his pressure and temp?
 

[orgopete]

… Would this be an electrophilic addition?

No, there is NaOH as catalyst. The CO2 is reacting with the phenoxide.

By the way, I think phenol is produced commercially from cumene. You could use benzene to make cumene and go from there. You may also do it in many other and what may seem more logically direct ways.

[Nescafe]

… Would this be an electrophilic addition?

No, there is NaOH as catalyst. The CO2 is reacting with the phenoxide.

By the way, I think phenol is produced commercially from cumene. You could use benzene to make cumene and go from there. You may also do it in many other and what may seem more logically direct ways.

Thanks!