Basic information
- CAS
79-42-5- Standard SMILES
CC(S)C(=O)O- InChIKey
PMNLUUOXGOOLSP-UHFFFAOYSA-N- Molecular formula
- C3H6O2S
- Average molar mass
- 106.15 g/mol
- Monoisotopic mass
- 106.00885043
Overview
Thiolactic acid appears as an oily liquid with an unpleasant odor. Toxic by ingestion and skin absorption. Used as a depilatory and in hair waving preparations.
Names & identifiers
- Preferred name
- (+-)-2-Mercaptopropionic acid
- IUPAC
- 2-sulfanylpropanoic acid
- English name
- 2-Mercaptopropionic acid
- Molecular formula
- C3H6O2S
- Molecular weight
- 106.14
Names & synonyms
Show more names
Database identifiers
- CAS
79-42-5- PubChem CID
- 62326
- DTXSID
DTXSID80861636- ChEMBL
CHEMBL2158192- ChEBI
CHEBI:47872- UNII
- O5U6967KGF
- EC Number
- 201-206-5
- Nikkaji
- J4.231E
Properties
Computed structural properties
- XLogP
- 0.5
- Topological polar surface area
- 38.3 Ų
- Hydrogen bond donors
- 2
- Hydrogen bond acceptors
- 3
- Rotatable bonds
- 1
- Heavy atoms
- 6
- Formal charge
- 0
- Complexity
- 61.8
Experimental & physicochemical properties
Chemical Classes
Other Classes -> Organic Acids
Flammable agents - 2nd degree
Solubility
miscible in water, alcohol, ether and acetone
1 mL in 1 mL 95% alcohol (in ethanol)
Boiling Point
117.00 °C. @ 16.00 mm Hg
117 °C
Physical Description
Thiolactic acid appears as an oily liquid with an unpleasant odor. Toxic by ingestion and skin absorption. Used as a depilatory and in hair waving preparations.
Liquid with a disagreeable odor; mp = 10 deg C; [Merck Index] Colorless liquid with a stench; mp = 10-14 deg C; [Alfa Aesar MSDS]
Liquid
colourless to pale yellow liquid with roasted, meaty odour
Physicochemical properties
- Melting point
- 10 · 10-14 °C (lit.)
- Boiling point
- 102 °C/16 · 102 °C/16 mmHg (lit.) 203-208 °C (lit.)
- Density
- 1.196 g/mL · 1.196 g/mL at 25 °C (lit.)
- vapor pressure
- 1.7 hPa · 1.7 hPa (20 °C)
- refractive index
- 20 · n20/D 1.481(lit.)
- FEMA
- 3180 · 3180 | 2-MERCAPTOPROPIONIC ACID
- FLAVIS Number
- 12.039 · 12.039 | 2-Mercaptopropionic acid
- Flash point
- 190 °F · 190 °F
- storage temp.
- 2 · 2-8°C
- solubility
- 1 g/L · 1g/L in organic solvents at 20 ℃
- pka
- 1 · pK1:4.32(0);pK2:10.20(SH) (25°C)
- form
- Liquid
- color
- Clear colorless to slightly yellow
- PH
- 2 · 2 (H2O, 20℃)(undiluted)
- Odor
- 0.01 % · at 0.01 % in propylene glycol. meaty sulfurous roasted
- Odor Type
- sulfurous
- biological source
- synthetic
- Water Solubility
- MISCIBLE
- JECFA Number
- 551 · 551
- Merck
- 14 · 14,9340
- BRN
- 506218 · 506218
- Cosmetics Ingredients Functions
- DEPILATORYANTIOXIDANTFRAGRANCEHAIR WAVING OR STRAIGHTENINGREDUCING
- InChI
- 1S/C3H6O2S/c1-2(6)3(4)5/h2,6H,1H3,(H,4,5)
- InChIKey
- PMNLUUOXGOOLSP-UHFFFAOYSA-N
- SMILES
- CC(S)C(O)=O
- LogP
- 1.15 at · 1.15 at 20℃
- Substances Added to Food (formerly EAFUS)
- 2 · 2-MERCAPTOPROPIONIC ACID
- CAS DataBase Reference
- 79 · 79-42-5(CAS DataBase Reference)
- EWG's Food Scores
- 1 · 1
- FDA UNII
- 5 U6967KGF · O5U6967KGF
- NIST Chemistry Reference
- 2 · 2-Mercaptopropanoic acid(79-42-5)
- EPA Substance Registry System
- 2 · Propanoic acid, 2-mercapto- (79-42-5)
- UNSPSC Code
- 12352106 · 12352106
- NACRES
- 22 · NA.22
- Symbol(GHS)
- 5 · GHS05,GHS06
- Signal word
- Danger
- Hazard statements
- 301 · H301+H331-H314
- Precautionary statements
- 501 · P501-P270-P261-P271-P264-P280-P303+P361+P353-P301+P330+P331-P363-P301+P310+P330-P304+P340+P310-P305+P351+P338+P310-P403+P233-P405
- PPE
- Faceshields, Gloves, Goggles, type ABEK (EN14387) respirator filter
- Hazard Codes
- C
- Risk Statements
- 34 · 34-22
- Safety Statements
- 26 · 26-36/37/39-45-25
- RIDADR
- 2936 · UN 2936
- WGK Germany
- 1 · 1
- RTECS
- 5250000 · UF5250000
- TSCA
- TSCA listed
- HazardClass
- 6.1 · 6.1
- PackingGroup
- II
- HS Code
- 29309070 · 29309070
- Storage Class
- 6.1 A · 6.1A - Combustible acute toxic Cat. 1 and 2very toxic hazardous materials
- Hazard Classifications
- 1 B · Skin Corr. 1B
- Toxicity
- 50 orally · LD50 orally in Rabbit: 730 mg/kg
- REACH Registrations
- Active
Safety & regulation
GHS classification
GHS Classification
Danger
H301 (86.3%): Toxic if swallowed [Danger Acute toxicity, oral]
P260, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P361+P364, P363, P403+P233, P405, and P501 (click each P-code to see the statement)
Aggregated GHS information provided per 1491 reports by companies from 10 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.
Hazard information
Regulatory Information
Chemical: Propanoic acid, 2-mercapto-
Status: Active Update: 23-05-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/26263
2-Mercaptopropionic acid: Does not have an individual approval but may be used under an appropriate group standard
The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)
Fire Hazards
Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:
· Combustible material: may burn but does not ignite readily.
Health Hazards
Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:
· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.
Reactivity Profile
THIOLACTIC ACID 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 it 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.
DOT Hazard Classification
Thiolactic acid
UN2936
Div 6.1 Poisonous materials (49 eCFR § 173.132)
PG II: the degree of danger presented by the material is medium
Hazard Classes and Categories
Acute Tox. 3 (86.3%)
Flammable agents - 2nd degree
Safety & protection
Accidental Release Measures
· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.
· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.
First Aid
Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:
General First Aid:
Isolation and Evacuation
Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:
Immediate precautionary measure
Toxicology
Safety data
- PPE
- Faceshields, Gloves, Goggles, type ABEK (EN14387) respirator filter
- wgk
- 1
- tsca
- TSCA listed
- rtecs
- UF5250000
- ridadr
- UN 2936
- hs_code
- 29309070
- Toxicity
- LD50 orally in Rabbit: 730 mg/kg
- risk_code
- 34-22
- Signal word
- Danger
- Symbol(GHS)
- GHS05,GHS06
- hazard_code
- C
- safety_code
- 26-36/37/39-45-25
- hazard_class
- 6.1
- Storage Class
- 6.1A - Combustible acute toxic Cat. 1 and 2very toxic hazardous materials
- packing_group
- II
- Hazard statements
- H301+H331-H314
- REACH Registrations
- Active
- Hazard Classifications
- Skin Corr. 1B
- Precautionary statements
- P501-P270-P261-P271-P264-P280-P303+P361+P353-P301+P330+P331-P363-P301+P310+P330-P304+P340+P310-P305+P351+P338+P310-P403+P233-P405
Chemistry & industry
Pharmacology
Uses & manufacturing
Uses
Used in depilatory and hair waving products; [Merck Index] Used as a flavoring agent; [FDA]
Dressing Hair [Category: Other]
Use Classification
Fragrance Ingredients
Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes
Flavoring Agents -> JECFA Flavorings Index
Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes
Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes
Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes
Applications
Uses2-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.
UsesDepilatory, hair-waving preparations.
UsesThiolactic acid (TLA) can be used as a building block in the synthesis of:Thiolactomycin via oxathiolanone intermediate.4-Thiazolidinones by reacting various Schiff bases with thioglycolic acid.1,4-Naphthoquinone derivatives containing sulfur atom for antibacterial and antiviral activity studies.It can also be used as a bidental chelating agent for the surface modification of titanium dioxide (TiO2) nanoparticles for the removal of cadmium from waste water.
General DescriptionAn oily liquid with an unpleasant odor. Toxic by ingestion and skin absorption. Used as a depilatory and in hair waving preparations.
Preparation methods
PreparationIt 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.
PreparationBy electrolysis of the corresponding sulfide, S(SCHMeCO2H)2.
Upstream & downstream products
Upstream raw materials
Downstream products
Suppliers102 total
Additional notes
DefinitionChEBI: 2-mercaptopropanoic acid is a mercaptopropanoic acid.
Related reactions
Compound notes
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