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.