Dimethyl acetylenedicarboxylate
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Dimethyl acetylenedicarboxylate | |
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General | |
Systematic name | Dimethyl acetylenedicarboxylate |
Other names | DMAD Acetylenedicarboxylic acid, dimethyl ester |
Molecular formula | C6H6O4 |
SMILES | O=C(OC)C#CC(OC)=O |
Molar mass | 142.11 g/mol |
Appearance | Colorless liquid |
CAS number | [762-42-5] |
Properties | |
Density and phase | 1.1564 g/cm3 |
Solubility in water | Insoluble |
Other solvents | Soluble in most organic solvents |
Melting point | -117 °C |
Boiling point | 195–198 °C 96–98° at 8 mm Hg |
Structure | |
Dipole moment | 0 D |
Hazards | |
MSDS | External MSDS |
Main hazards | Toxic gas |
NFPA 704 | |
Flash point | 187 °F |
R/S statement | R: R34 S: S23 S26 S27 S36/37/39 S45 |
RTECS number | ES0175000 |
Supplementary data page | |
Structure and properties |
n = 1.447 |
Thermodynamic data |
Phase behaviour Solid, liquid, gas |
Spectral data | UV, IR, NMR, MS |
Related compounds | |
Related compounds | Methyl propiolate, Hexafluoro-2-butyne, Acetylene |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Dimethyl acetylenedicarboxylate (DMAD) is the organic compound with the formula CH3O2CC2CO2CH3. This alkyne, which exists as a liquid at room temperature, is highly electrophilic. As such, DMAD, as it is commonly called in the laboratory, is widely employed as a dienophile in cycloaddition reactions, such as the Diels-Alder reaction. It is also a potent Michael acceptor.[1]
Contents |
[edit] Preparation
Although inexpensively available, DMAD is prepared today as it was originally.[2] Maleic acid is brominated and the resulting dibromosuccinic acid is dehydrohalogenated.[3] The dicarboxylic acid is then esterified with methanol and sulfuric acid as a catalyst.[4]
[edit] Safety
DMAD is a lachrymator and a vesicant.
[edit] 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.
- ^ Bandrowski, E. “Ueber Acetylendicarbonsäure” Chemische Berichte band 10, 838 (1877).
- ^ Abbott, T. W.; Arnold, R. T.; Thompson, R. B. “Acetylenedicarboxyltic acid” Organic Syntheses, Collective Volume 2, page 10.
- ^ Huntress, E. H. Lesslie, T. E.; Bornstein, J. “Dimethyl Acetylenedicarboxylate” Organic Syntheses, Collective Volume 4, page 329.