Acetylenedicarboxylic acid dimethyl ester

Structural formula
General
Surname	Acetylenedicarboxylic acid dimethyl ester
other names	DMAD; 2-butynedioic acid dimethyl ester; Dimethylacetylenedicarboxylate;
Molecular formula	C 6 H 6 O 4
Brief description	slightly yellowish liquid
External identifiers / databases
EC number	212-098-4
ECHA InfoCard	100.010.999
PubChem	12980
Wikidata	Q904788
properties
Molar mass	142.11 g mol −1
Physical state	liquid
density	1.16 g cm −3 (20 ° C)
Melting point	−18 ° C
boiling point	195-198 ° C
solubility	almost insoluble in water
Refractive index	1.447
safety instructions
H and P phrases	H: 314-335
	P: 280-301 + 330 + 331-304 + 340-305 + 351 + 338-309 + 310
Toxicological data	550 mg kg −1 ( LD 50 , mouse , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Acetylenedicarboxylic acid dimethyl ester (DMAD) is an organic chemical compound with the formula C ₆ H ₆ O ₄ from the group of carboxylic acid esters with a C≡C triple bond.

Extraction and presentation

Maleic acid is brominated and the resulting dibromo succinic acid with potassium hydroxide dehydrohalogenated. The resulting acetylenedicarboxylic acid is then esterified with methanol and sulfuric acid as a catalyst .

properties

Acetylenedicarboxylic acid dimethyl ester is a pale yellowish liquid that decomposes when heated or when exposed to light.

use

As an alkyne that is liquid at room temperature, DMAD is highly electrophilic . It is therefore used as a dienophile in cycloaddition reactions - such as the Diels-Alder reaction . It is also a strong Michael acceptor .

safety instructions

Acetylenedicarboxylic acid dimethyl ester is an irritant and a corrosive agent . Contact with metals can produce hydrogen, which creates a risk of explosion.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ data sheet for dimethyl acetylenedicarboxylate (PDF) from Merck , accessed on March 2, 2013.
↑ ^a ^b Datasheet Dimethyl acetylenedicarboxylate from Sigma-Aldrich , accessed on March 20, 2011 ( PDF ).
↑ Data sheet Dimethyl Acetylenedicarboxylate (PDF) from Fisher Scientific , accessed on February 13, 2014.

[MERCK-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ data sheet for dimethyl acetylenedicarboxylate (PDF) from Merck , accessed on March 2, 2013.

[Sigma-2] Datasheet Dimethyl acetylenedicarboxylate from Sigma-Aldrich , accessed on March 20, 2011 ( PDF ).

[3] Data sheet Dimethyl Acetylenedicarboxylate (PDF) from Fisher Scientific , accessed on February 13, 2014.