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.

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.[6][7]

References

  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.
  6. ^ Klain, G (May 1988). "Metabolic alterations induced by topical dimethylacetylenedicarboxylate*1". Fundamental and Applied Toxicology. 10 (4): 730–735. doi:10.1016/0272-0590(88)90199-6.
  7. ^ Slovak, A. J. M.; Payne, A. R. (June 1984). "Delayed dermal burns caused by dimethyl acetylenedicarboxylate". Contact Dermatitis. 11 (1): 29–30. doi:10.1111/j.1600-0536.1984.tb00166.x. ISSN 0105-1873.
Allikas: https://en.wikipedia.org/wiki/DMAD
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