Synthesis, purification, and metal complex formation properties of methyl 3-mercaptopropionate and solubility and stability constants of meso-2,3-dimercaptosuccinic aci

Methyl 3-mercaptopropionate was synthesized from 3-mercaptopropionic acid and purified by extraction into chloroform and column chromatography. The percent purity of the purchased material was determined by an iodine titration. Methyl 3-mercaptopropionate formed an insoluble complex with lead (II) when the pH was greater than 3. It also complexed with cobalt (II).;The solubility of meso-dimercaptosuccinic acid was estimated by a spectrophotometric method using 5,5-dithiobis(2-nitrobenzoic acid) since the iodine titration did not give quantitative results. The acid dissociation constants were determined potentiometrically; two methods of calculation were used. Attempts to prepare crystals of the lead (II) complex of meso-dimercaptosuccinic acid in the following gels: agar, agarose, and gelatin, were unsuccessful.