| Dimethyl acetylenedicarboxylate | |
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Dimethyl but-2-ynedioate |
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Other names
DMAD |
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| Identifiers | |
| CAS number | 762-42-5 |
| ChemSpider | 12440 |
| RTECS number | ES0175000 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C6H6O4 |
| Molar mass | 142.11 g/mol |
| Appearance | Colorless liquid |
| Density | 1.1564 g/cm³ |
| Melting point |
c |
| Boiling point |
195–198 °C |
| Solubility in water | Insoluble |
| Solubility in other solvents | Soluble in most organic solvents |
| Refractive index (nD) | 1.447 |
| Structure | |
| Dipole moment | 0 D |
| Hazards | |
| R-phrases | R34 |
| S-phrases | S23 S26 S27 S36/37/39 S45 |
| Main hazards | Toxic gas |
| Flash point | 187 °F |
| Related compounds | |
| Related compounds | Methyl propiolate, Hexafluoro-2-butyne, Acetylene |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Dimethyl acetylenedicarboxylate (DMAD) is the organic compound with the formula CH3O2CC2CO2CH3. This ester, 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][2]
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]
DMAD is a lachrymator and a vesicant.