| Identification | More | [Name]
2-Mercaptopropionic acid | [CAS]
79-42-5 | [Synonyms]
2-MERCAPTOPROPIONIC ACID
ALPHA-MERCAPTOPROPIONIC ACID
FEMA 3180
FEMA 3810
PROPANOIC ACID, 2-MERCAPTO-
THIOLACTIC ACID
2-mercapto-propanoicaci
2-mercaptopropanoicacid
2-mercapto-Propanoicacid
2-mercapto-propionicaci
2-Sulfanylpropanoic acid
2-Thiolactic acid
2-thiolacticacid
alpha-Mercaptopropanoic acid
alpha-mercaptopropanoicacid
Propionic acid, 2-mercapto-
thiolactic
2-Mercaptopropanic Acid
Thiolacticacid,95%
2-MERCAPTOPROPIONIC ACID 95+% | [EINECS(EC#)]
201-206-5 | [Molecular Formula]
C3H6O2S | [MDL Number]
MFCD00004862 | [Molecular Weight]
106.14 | [MOL File]
79-42-5.mol |
| Chemical Properties | Back Directory | [Appearance]
Clear colorless to slightly yellow liquid | [Melting point ]
10-14 °C (lit.) | [Boiling point ]
102 °C/16 mmHg (lit.)
203-208 °C (lit.) | [density ]
1.196 g/mL at 25 °C(lit.)
| [vapor pressure ]
1.7 hPa (20 °C) | [FEMA ]
3180 | [refractive index ]
n20/D 1.481(lit.)
| [Fp ]
190 °F
| [storage temp. ]
2-8°C | [solubility ]
1g/L in organic solvents at 20 ℃ | [form ]
Liquid | [pka]
pK1:4.32(0);pK2:10.20(SH) (25°C) | [color ]
Clear colorless to slightly yellow | [Odor]
at 0.01 % in propylene glycol. meaty sulfurous roasted | [PH]
2 (H2O, 20℃)(undiluted) | [Odor Type]
sulfurous | [Water Solubility ]
MISCIBLE | [JECFA Number]
551 | [Merck ]
14,9340 | [BRN ]
506218 | [InChIKey]
PMNLUUOXGOOLSP-UHFFFAOYSA-N | [LogP]
1.15 at 20℃ | [Uses]
Depilatory, hair-waving preparations. | [CAS DataBase Reference]
79-42-5(CAS DataBase Reference) | [NIST Chemistry Reference]
2-Mercaptopropanoic acid(79-42-5) | [EPA Substance Registry System]
79-42-5(EPA Substance) |
| Safety Data | Back Directory | [Hazard Codes ]
C | [Risk Statements ]
R34:Causes burns.
R22:Harmful if swallowed. | [Safety Statements ]
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S25:Avoid contact with eyes . | [RIDADR ]
UN 2936 6.1/PG 2
| [WGK Germany ]
1
| [RTECS ]
UF5250000
| [TSCA ]
Yes | [HazardClass ]
6.1 | [PackingGroup ]
II | [HS Code ]
29309070 | [Safety Profile]
Poison by ingestion.
Moderately toxic by inhalation. When
heated to decomposition it emits toxic
fumes of SOx. See also SULFIDES and
MERCAPTANS. | [Toxicity]
LD50 orally in Rabbit: 730 mg/kg |
| Hazard Information | Back Directory | [General Description]
An oily liquid with an unpleasant odor. Toxic by ingestion and skin absorption. Used as a depilatory and in hair waving preparations. | [Reactivity Profile]
THIOLACTIC ACID(79-42-5) is an organosulfide/organic acid. Organosulfides are incompatible with acids, diazo and azo compounds, halocarbons, isocyanates, aldehydes, alkali metals, nitrides, hydrides, and other strong reducing agents. Reactions with these materials generate heat and in many cases hydrogen gas. Many of these compounds may liberate hydrogen sulfide upon decomposition or reaction with an acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in THIOLACTIC ACID(79-42-5) to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions. | [Air & Water Reactions]
Soluble in water and denser than water. | [Health Hazard]
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. | [Fire Hazard]
Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form. | [Chemical Properties]
Clear colorless to slightly yellow liquid.
Oily liquid; Melting point 10 ℃; Boiling point d-95 ~ 100 ℃ / 2133Pa, dl- 98.5 ~ 99.0 ℃ / 1866Pa; Density I-D19.24 1.193; Refractive index dl-nD: 1.4823; Optical rotation[α] D-45.47; soluble in water, ethanol and ether.
| [Chemical Properties]
Thiolactic acid has a roasted, meaty odor. | [Definition]
ChEBI:2-mercaptopropanoic acid is a mercaptopropanoic acid. | [Taste threshold values]
Taste characteristics at 15 ppm: meaty, sulfury, brothy, and brown. |
| Questions And Answer | Back Directory | [Uses]
2-Mercaptopropionic acid is an important raw material for organic synthesis, mainly used in the preparation of herbicides, plasticized heat stabilizers and antioxidants, as well as the deployment of daily spices.
| [Preparation]
It is prepared from the electrolysis of the corresponding sulfide S (SCHMeCO2H) Alternatively, it can be prepared from the reaction between pyruvate and hydrogen sulfide. Hydrogen sulfide is added to 50% pyruvic acid to make it saturated at 60-70 DEG C; add hydrochloric acid to until turbidity is formed; dilute sulfuric acid is added to make it weakly acidic, and 2.5% sodium amalgam is added to the precipitated compound for reduction. Cool it till hydrogen sulfide is completed released. Then add ether the acidic medium, extract the lactic acid, remove the ether by distillation, here thiolactic acid is finally obtained.
| [Content Assay]
Accurately weigh 1 g of sample, transfer it into a 250ml Erlenmeyer flask filled with 75 ml of water; add phenolphthalein indicator (TS-167); use 0.5mol / L NaOH solution for titration. Each ml of 0.5mol / L NaOH solution is equivalent to 53.08 mg of 2-mercaptopropionic acid. | [Storage and transportation]
Store in a cool and ventilated place, the container should be sealed to prevent damp, heat, handling gently, can’t be inverted, and be careful not to damage the packaging.
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