Originally posted by Nicodem
It won't hydrolyze at room temperature even at pH 1.
There was no need to neutralize, but it won't hurt either as its pKa1 is about 9 so even if you added excess NaHCO3 it will barely increase any
solubility by deprotonation. A more important thing would be to quench all the remaining oxidant species with sulfite or whatever.
Extraction is not wise due to the unfavorable partition coefficients. So you are left with either:
A.) evaporating the water out, extracting the solids with ethanol (or acetone, i-PrOH or what you have), evaporating the solvent and recrystallization
from water;
B.) saturating with NaCl, waiting for 5,5-dimethylhydantoin to crystallize out, filtering and recrystallization.
Of course, method A would give you more product, but evaporating a liter of water down without using vacuum sucks a lot. |