Sciencemadness Discussion Board

help in selecting solvent for synthesis of phenolphthalein.

vibbzlab - 12-3-2020 at 07:53

I was going through various solvents for extracting phenolphthalein after its synthesis. I saw dichloromethane(DCM) is very good solvent and helps preferentially extract out phenolphthalein.
but problem is I don't have access to that. I wanted to know whether chloroform works or is there any other simpler method to extract it

njl - 12-3-2020 at 09:06

I have no experience making phenolphthalein, but I'd guess that chloroform isn't ideal as it's more polar than dcm (the ideal). The most accessible non-polar solvents are probably straight chain hydrocarbons like butane (from lighter refills) or heptane (starter fluid spray).

medchemist - 12-3-2020 at 13:12

for extraction what are we trying to extract it from? i.e. what are the reagents used to make it?
A suitable solvent would be ethyl acetate at that is decent for most extractions and is not as nasty health-wise as DCM or chloroform.
Doing multiple extractions with a small volume of solvent is far better than few/one extraction with loads of solvent as you're relying on an equilibrium between the aqueous and organic solvents - so even 'poor' solvents are fine for extraction so long as what you want is more soluble in the solvent than it is in water.

vibbzlab - 12-3-2020 at 18:05

i made it in the classical method ; phenol and phthalic anhydride with sulfuric acid