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| Names | |
|---|---|
| IUPAC name (2E)-but-2-enal | |
| Other names Crotonaldehyde Crotonic aldehyde β-Methacrolein β-Methyl acrolein 2-butenal Propylene aldehyde | |
| Identifiers | |
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3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| DrugBank |
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| ECHA InfoCard | 100.021.846 |
| EC Number |
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| KEGG |
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| RTECS number |
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| UNII |
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| UN number | 1143 |
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| Properties ((E) isomer) | |
| C4H6O | |
| Molar mass | 70.091 g·mol−1 |
| Appearance | colourless liquid |
| Odor | pungent, suffocating odor |
| Density | 0.846 g/cm3 |
| Melting point | −76.5 °C (−105.7 °F; 196.7 K) |
| Boiling point | 104.0 °C (219.2 °F; 377.1 K) |
| 18% (20 °C)[2] | |
| Solubility | very soluble inethanol,ethyl ether,acetone soluble inchloroform miscible inbenzene |
| Vapor pressure | 19 mmHg (20 °C)[2] |
Refractive index (nD) | 1.4362 |
| Hazards | |
| GHS labelling: | |
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| Danger | |
| H225,H301,H310,H311,H315,H318,H330,H335,H341,H373,H400 | |
| P201,P202,P210,P233,P240,P241,P242,P243,P260,P261,P262,P264,P270,P271,P273,P280,P281,P284,P301+P310,P302+P350,P302+P352,P303+P361+P353,P304+P340,P305+P351+P338,P308+P313,P310,P312,P314,P320,P321,P322,P330,P332+P313,P361,P362,P363,P370+P378,P391,P403+P233,P403+P235,P405,P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 13 °C (55 °F; 286 K) |
| 207 °C (405 °F; 480 K) | |
| Explosive limits | 2.1–15.5% |
| Lethal dose or concentration (LD, LC): | |
LC50 (median concentration) | 600 ppm (rat, 30 min) 1375 ppm (rat, 30 min) 519 ppm (mouse, 2 hr) 1500 ppm (rat, 30 min)[3] |
LCLo (lowest published) | 400 ppm (rat, 1 hr)[3] |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 2 ppm (6 mg/m3)[2] |
REL (Recommended) | TWA 2 ppm (6 mg/m3)[2] |
IDLH (Immediate danger) | 50 ppm[2] |
| Related compounds | |
Related alkenals | Acrolein |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Crotonaldehyde is achemical compound with theformula CH3CH=CHCHO. The compound is usually sold as a mixture of theE- andZ-isomers, which differ with respect to the relative position of themethyl andformyl groups. TheE-isomer is more common. Thislachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate inorganic synthesis. It occurs in a variety of foodstuffs, e.g.soybean oils.[4]
Crotonaldehyde is produced by thealdol condensation ofacetaldehyde:
Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is aprochiral dienophile.[5] It is aMichael acceptor. Addition ofmethylmagnesium chloride produces 3-penten-2-ol.[6]
It is a precursor to many fine chemicals. A prominent industrial example is the crossed aldol condensation withdiethyl ketone to give trimethylcyclohexenone, this can be easily converted to trimethylhydroquinone, which is a precursor to thevitamin E.[8] Other derivatives include crotonic acid, 3-methoxybutanol and the food preservativeSorbic acid. Condensation with two equivalents ofurea gives apyrimidine derivative that is employed as acontrolled-release fertilizer.[4]
Crotonaldehyde is a potent irritant even at the ppm levels. It is not very toxic, with anLD50 of 174 mg/kg (rats, oral).[4]
