3-methyl-1,2-butadiene

Structural formula
General
Surname	3-methyl-1,2-butadiene
other names	1,1-dimethylallene; 3-methylbuta-1,2-diene;
Molecular formula	C 5 H 8
Brief description	colorless liquid
External identifiers / databases
ECHA InfoCard	100.009.025
PubChem	11714
ChemSpider	11222
Wikidata	Q24711948
properties
Molar mass	68.12 g mol −1
Physical state	liquid
density	0.694 g cm −3 (25 ° C)
Melting point	−148 ° C
boiling point	40-41 ° C
Vapor pressure	473.6 hPa (20 ° C)
solubility	soluble in diethyl ether , benzene , acetone and ethanol
Refractive index	1.419 (20 ° C)
safety instructions
H and P phrases	H: 225-304-315-319-335
	P: 210-261-301 + 310-305 + 351 + 338-331
	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

3-Methyl-1,2-butadiene is a chemical compound belonging to the alkadienes group .

Extraction and presentation

3-Methyl-1,2-butadiene can be obtained by reacting 1,1-dichloro-2-ethoxy-3,3-dimethylcyclopropane with methyllithium and diethyl ether.

3-methyl-1,2-butadiene is a colorless liquid that is soluble in diethyl ether , benzene , acetone and ethanol .

3-Methyl-1,2-butadiene is used to study the photo-induced reaction with the cyanoarenes 1,2,4,5-tetracyanobenzene , 1,4-dicyanobenzene and 1,4-dicyanonaphthalene in the presence of methanol as the nucleophile .

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ data sheet 3-methyl-1,2-butadiene, 97% from Sigma-Aldrich , accessed on August 12, 2019 ( PDF ).
↑ ^a ^b ^c data sheet 3-methyl-1,2-butadiene, 97 +% from AlfaAesar, accessed on August 12, 2019 ( PDF )(JavaScript required) .
^ Lars Skattebøl: Chemistry of gem-Dihalocyclopropanes. IV. Ring Opening of gem-Dichlorocyclopropyl Ethers. In: The Journal of Organic Chemistry . 31, 1966, pp. 1554-1559, doi : 10.1021 / jo01343a057 .
↑ PrepChem.com: Synthesis of 3-methylbuta-1,2-diene - PrepChem.com , access date : August 12, 2019.