1,2-Butanediol
Chemical compound
From Wikipedia, the free encyclopedia
1,2-Butanediol is the organic compound with the formula HOCH2(HO)CHCH2CH3. It is classified as a vic-diol (glycol). It is chiral, although typically it is encountered as the racemic mixture. It is a colorless liquid.
| |
 | |
| Names | |
|---|---|
| Preferred IUPAC name
Butane-1,2-diol | |
| Other names
1,2-Dihydroxybutane α-Butylene glycol | |
| Identifiers | |
| |
3D model (JSmol) |
|
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.008.663 |
| EC Number |
|
PubChem CID |
|
| RTECS number |
|
| UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties[1] | |
| C4H10O2 | |
| Molar mass | 90.121 g/mol |
| Density | 1.0023 g/cm3 (20 °C) |
| Melting point | −50 °C (−58 °F; 223 K)[note 1] |
| Boiling point | 195 to 196.9 °C (383.0 to 386.4 °F; 468.1 to 470.0 K) (96.5 °C at 10 mmHg) |
| miscible | |
| Solubility | soluble in ethanol, acetone; sparingly soluble in esters and ethers; insoluble in hydrocarbons |
Refractive index (nD) |
1.4378 (20 °C) |
| Viscosity | 7.3 mPa·s (20 °C) |
| Thermochemistry | |
Std enthalpy of formation (ΔfH⦵298) |
−532.8 kJ/mol [2] |
Std enthalpy of combustion (ΔcH⦵298) |
−2479 kJ/mol |
| Hazards[3] | |
| Flash point | 90 °C (194 °F; 363 K) |
| Safety data sheet (SDS) | ICSC 0395 |
| Related compounds | |
Related butanediols |
1,3-Butanediol 1,4-Butanediol 2,3-Butanediol |
Related compounds |
Ethylene glycol Propylene glycol 2-Hydroxybutyraldehyde 2-Hydroxybutyric acid α-Ketobutyric acid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Preparation
This diol was first described by Charles-Adolphe Wurtz in 1859.[4]
It is produced industrially by hydration of 1,2-epoxybutane.[5][6]
This process requires a ten- to twenty-fold excess of water to suppress the formation of polyethers. Depending on the amount of excess water, the selectivity varies from 70 to 92%.[7] Sulfuric acid or strongly acidic ion exchange resins may be used as catalysts, which allows the reaction to occur under 160 °C and at slightly above atmospheric pressure.
1,2-Butanediol is a byproduct of the production of 1,4-butanediol from butadiene.[8] It is also a byproduct of the catalytic hydrocracking of starches and sugars such as sorbitol to ethylene glycol and propylene glycol.[9]
It can also be obtained from the dihydroxylation of but-1-ene by OsO4.
Applications
It has been patented for the production of polyester resins and plasticizers.[6][8] It is a potential feedstock for the industrial production of α-ketobutyric acid, a precursor to some amino acids.[10]
Safety
Notes
- The value of −50 °C for the melting point is taken from Ullmann's Encyclopedia of Industrial Chemistry and used by the Hazardous Substances Data Bank and the OECD Screening Information Dataset. Other reported values of the melting point range from −114 °C to −30 °C.