DL-mercaptosuccinic acid

DL-mercaptosuccinic acid structural formula

DL-mercaptosuccinic acid structural formula

Structural formula

Business number 01G5
Molecular formula C4H6O4S
Molecular weight 150.15

Thiomalic acid,

thiomalic acid,

Mercaptosuccinic acid,

Thiosuccinic acid,

Thiomalic acid,


Numbering system

CAS number:70-49-5

MDL number:MFCD00004860

EINECS number:200-736-4

RTECS number:WM8225000

BRN number:1099858

PubChem number:24889100

Physical property data

1. Properties: colorless crystals or white powder. There is an odor of sulfide

2. Density (g/mL, 25/4℃): Uncertain

3. Relative vapor density (g/mL, air=1): Uncertain

4. Melting point (ºC): 149-1505. Boiling point (ºC, normal pressure): Uncertain

6. Boiling point (ºC, 5.2kPa): Uncertain

7 .       Refractive index: Uncertain

8.       Flash point (ºC): Uncertain

9.       Specific rotation (º): Uncertain

10. Autoignition point or ignition temperature (ºC): Uncertain

11. Vapor pressure (kPa, 25ºC): Uncertain

12. Saturated vapor pressure (kPa, 60ºC): Uncertain Determine

13. Heat of combustion (KJ/mol): Uncertain

14. Critical temperature (ºC): Uncertain

15. Critical pressure (KPa ): Uncertain

16. Log value of oil-water (octanol/water) partition coefficient: Uncertain

17. Explosion upper limit (%, V/V): Uncertain

18. Lower explosion limit (%, V/V): Uncertain

19. Solubility: Easily soluble in water, alcohol, ether and acetone, almost insoluble in benzene

Toxicological data

Acute toxicity: mouse abdominal LD50: 200 mg/kg;

Ecological data


Molecular structure data

1. Molar refractive index: 31.56

2. Molar volume (cm3/mol): 98.2

3. Isotonic specific volume (90.2K ): 284.1

4. Surface tension (dyne/cm): 69.9

5. Polarizability (10-24cm3): 12.51

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): -0.4

2. Number of hydrogen bond donors: 3

3. Number of hydrogen bond acceptors: 5

4. Number of rotatable chemical bonds: 3

5. Number of tautomers: none

6. Topological molecule polar surface area 75.6

7. Number of heavy atoms: 9

8. Surface charge: 0

9. Complexity: 133

10. Number of isotope atoms: 0

11. Determine the atomic stereocenter Quantity: 0

12. Uncertain number of atomic stereocenters: 1

13. Determined number of chemical bond stereocenters: 0

14. Uncertain chemical bonds Number of stereocenters: 0

15. Number of covalent bond units: 1

Properties and stability


Storage method

This product should be sealed, cool, dry and protected from light.

Synthesis method

Hydration of maleic anhydride produces maleic acid, which is then reacted with hydrogen sulfide to produce this product. For laboratory preparation, 23.2g malic acid and 20g thioacetic acid can be dissolved in 80ml ethyl acetate and refluxed for 1 hour. After cooling, add 400 ml of benzene to extract, add activated carbon for decolorization, filter to remove the carbon, and recover benzene to obtain crude product. After purification, 32g of acetylthiomalic acid was obtained, with a melting point of 126°C. Further hydrolysis yields mercaptosuccinic acid.


This product is the main component of cold perm and is also used in complex concealment, biochemical research, heavy metal detoxifier and rubber industry.