Dimethyl acetylenedicarboxylate

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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. This compound was used in the preparation of nedocromil.

Dimethyl acetylenedicarboxylate
Chemical structure of DMADuak
Ball-and-stick model
Names
Preferred IUPAC name
Dimethyl but-2-ynedioate
Other names
DMAD
Acetylenedicarboxylic
acid dimethyl ester
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.010.999 Edit this at Wikidata
EC Number
  • 212-098-4
RTECS number
  • ES0175000
UNII
  • InChI=1S/C6H6O4/c1-9-5(7)3-4-6(8)10-2/h1-2H3 checkY
    Key: VHILMKFSCRWWIJ-UHFFFAOYSA-N checkY
  • InChI=1/C6H6O4/c1-9-5(7)3-4-6(8)10-2/h1-2H3
    Key: VHILMKFSCRWWIJ-UHFFFAOYAX
  • COC(=O)C#CC(=O)OC
Properties
C6H6O4
Molar mass 142.11 g/mol
Appearance Colorless liquid
Density 1.1564 g/cm3
Melting point −18 °C (0 °F; 255 K)
Boiling point 195 to 198 °C (383 to 388 °F; 468 to 471 K) (96–98° at 8 mm Hg)
Insoluble
Solubility in other solvents Soluble in most
organic solvents
1.447
Structure
0 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Toxic
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation mark
Danger
H302, H314
P260, P264, P270, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P363, P405, P501
Flash point 187 °C (369 °F; 460 K)
Related compounds
Related compounds
Methyl propiolate,
Hexafluoro-2-butyne,
Acetylene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation

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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

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DMAD is a lachrymator and a vesicant.[citation needed]

References

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  1. ^ 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:10.1002/047084289X.
  2. ^ Sahoo, Manoj (2007). "Dimethyl Acetylene Dicarboxylate". Synlett. 2007 (13): 2142–2143. doi:10.1055/s-2007-984894.
  3. ^ Bandrowski, E. (1877). "Ueber Acetylendicarbonsäure". Berichte der Deutschen Chemischen Gesellschaft. 10: 838–842. doi:10.1002/cber.187701001231.
  4. ^ Abbott, T. W.; Arnold, R. T.; Thompson, R. B. (1938). "Acetylenedicarboxylic acid". Organic Syntheses. 18: 3. doi:10.15227/orgsyn.018.0003; Collected Volumes, vol. 2, p. 10.
  5. ^ Huntress, E. H.; Lesslie, T. E.; Bornstein, J. (1952). "Dimethyl Acetylenedicarboxylate". Organic Syntheses. 32: 55. doi:10.15227/orgsyn.032.0055; Collected Volumes, vol. 4, p. 329.