Dimethyl acetylenedicarboxylate
Names | |
---|---|
IUPAC name
Dimethyl but-2-ynedioate
| |
Other names
DMAD
Acetylenedicarboxylic acid dimethyl ester | |
Identifiers | |
3D model (JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.010.999 |
RTECS number |
|
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C6H6O4 | |
Molar mass | 142.11 g/mol |
Appearance | Colorless liquid |
Density | 1.1564 g/cm³ |
Melting point | c |
Boiling point | 195–198 °C 96–98° at 8 mm Hg |
Insoluble | |
Solubility in other solvents | Soluble in most organic solvents |
Refractive index (nD)
|
1.447 |
Structure | |
0 D | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
|
Toxic gas |
Flash point | 187 °C (369 °F; 460 K) |
Related compounds | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Dimethyl acetylenedicarboxylate (DMAD) is an organic compound with the formula CH3O2CC2CO2CH3. It is a di-ester in which the ester groups are conjugated with a C-C triple bond. As such, the molecule is highly electrophilic, and is widely employed as a dienophile in cycloaddition reactions, such as the Diels-Alder reaction. It is also a potent Michael acceptor.[1][2]This compound exists as a colorless liquid at room temperature.
Preparation
Although inexpensively available, DMAD is prepared today as it was originally. Maleic acid is brominated and the resulting dibromosuccinic acid is dehydrohalogenated with potassium hydroxide yielding acetylenedicarboxylic acid.[3][4] The acid is then esterified with methanol and sulfuric acid as a catalyst:[5]
Safety
DMAD is a lachrymator and a vesicant.
References
- ^ Stelmach, J. E.; Winkler, J. D. "Dimethyl Acetylenedicarboxylate"in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289.
- ^ Sahoo, Manoj (2007). "Dimethyl Acetylene Dicarboxylate". Synlett. 2007: 2142. doi:10.1055/s-2007-984894.
- ^ Bandrowski, E. (1877). "Ueber Acetylendicarbonsäure". Berichte der deutschen chemischen Gesellschaft. 10: 838. doi:10.1002/cber.187701001231.
- ^ Abbott, T. W.; Arnold, R. T.; Thompson, R. B. "Acetylenedicarboxylic acid". Organic Syntheses
{{cite journal}}
: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 2, p. 10. - ^ Huntress, E. H. Lesslie, T. E.; Bornstein, J. "Dimethyl Acetylenedicarboxylate". Organic Syntheses
{{cite journal}}
: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 4, p. 329.