Crotonaldehyde
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| Names | |
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| IUPAC name
(2E)-but-2-enal
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| Other names
Crotonaldehyde
Crotoinic aldehyde β-Methacrolein β-Methyl acrolein 2-butenal Propylene aldehyde | |
| Identifiers | |
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3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
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| DrugBank | |
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| KEGG | |
PubChem CID
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| UNII |
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| UN number | 1143 |
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| Properties | |
| 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 in ethanol, ethyl ether, acetone soluble in chloroform miscible in benzene |
| Vapor pressure | 19 mmHg (20°C)[2] |
Refractive index (nD)
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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) | <imagemap>
File:NFPA 704.svg|80px|alt=NFPA 704 four-colored diamond poly 150 150 300 300 150 450 0 300 Health 4: Very short exposure could cause death or major residual injury. E.g. VX gas poly 300 0 450 150 300 300 150 150 Flammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasoline poly 450 150 600 300 450 450 300 300 Instability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorus poly 300 300 450 450 300 600 150 450 Special hazards (white): no code desc none </imagemap> |
| 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)
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600 ppm (rat, 30 min) 1375 ppm (rat, 30 min) 519 ppm (mouse, 2 hr) 1500 ppm (rat, 30 min)[3] |
LCLo (lowest published)
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400 ppm (rat, 1 hr)[3] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 2 ppm (6 mg/m3)[2] |
REL (Recommended)
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TWA 2 ppm (6 mg/m3)[2] |
IDLH (Immediate danger)
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50 ppm[2] |
| Related compounds | |
Related alkenals
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Acrolein |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Crotonaldehyde is a chemical compound with the formula CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis. It occurs in a variety of foodstuffs, e.g. soybean oils.[4]
Production and reactivity
Crotonaldehyde is produced by the aldol condensation of acetaldehyde:
- 2 CH3CHO → CH3CH=CHCHO + H2O
Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is a prochiral dienophile.[5] It is a Michael acceptor. Addition of methylmagnesium chloride produces 3-penten-2-ol.[6]
Polyurethane catalyst N,N,N′,N′-tetramethyl-1,4-butanediamine (also known as NIAX TMBDA) was obtained by hydrogenating the reaction product of crotonaldehyde and dimethylamine.[7]
Uses
It is a precursor to many fine chemicals. A prominent industrial example is the crossed aldol condensation with diethyl ketone to give trimethylcyclohexenone, this can be easily converted to trimethylhydroquinone, which is a precursor to the vitamin E.[9] Other derivatives include crotonic acid, 3-methoxybutanol and the food preservative Sorbic acid. Condensation with two equivalents of urea gives a pyrimidine derivative that is employed as a controlled-release fertilizer. [4]
Safety
Crotonaldehyde is a potent irritant even at the ppm levels. It is not very toxic, with an LD50 of 174 mg/kg (rats, oral).[4]
See also
References
- ^ Merck Index, 11th Edition, 2599
- ^ 2.0 2.1 2.2 2.3 2.4 NIOSH Pocket Guide to Chemical Hazards. "#0157". National Institute for Occupational Safety and Health (NIOSH).
- ^ 3.0 3.1 "Crotonaldehyde". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ 4.0 4.1 4.2 R. P. Schulz; J. Blumenstein; C. Kohlpaintner (2005). "Crotonaldehyde and Crotonic Acid". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_083. ISBN 978-3527306732.
- ^ Longley Jr., R. I..; Emerson, W. S.; Blardinelli, A. J. (1954). "3,4-Dihydro-2-methoxy-4-methyl-2H-pyran". Org. Synth. 34: 29. doi:10.15227/orgsyn.034.0029.
- ^ Coburn, E. R. (1947). "3-Penten-2-ol". Org. Synth. 27: 65. doi:10.15227/orgsyn.027.0065.
- ^ "Catalysts". 8 January 2011.
- ^ Dittmar, Heinrich; Drach, Manfred; Vosskamp, Ralf; Trenkel, Martin E.; Gutser, Reinhold; Steffens, Günter (2009). "Fertilizers, 2. Types". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.n10_n01. ISBN 978-3527306732.
- ^ Müller, Marc-André; Schäfer, Christian; Litta, Gilberto; Klünter, Anna-Maria; Traber, Maret G.; Wyss, Adrian; Ralla, Theo; Eggersdorfer, Manfred; Bonrath, Werner (6 December 2022). "100 Years of Vitamin E: From Discovery to Commercialization" (PDF). European Journal of Organic Chemistry. 2022 (45). doi:10.1002/ejoc.202201190.