Hepaldine,Riker,France,1964
Cysteine is first dissolved in distilled water which has been freed of oxygen by
boiling. Formaldehyde of 30% (w/v) concentration is added while stirring and
the temperature of the mixture rises, while the thiazolidine carboxylic acid
begins crystallizing. The stirring is continued for 2 hours after which ethyl
alcohol of 95% (w/v) concentration is added to induce further crystallization.
The mixture is left to stand for 24 hours at 4°C. The mixture is then filtered
with retention of a crude product, which is purified by recrystallization from
boiling distilled water. The crystals are then dried at about 40°C. The free acid
is then converted to the sodium salt with NaOH.
Hepatoprotectant, Choleretic
