Crotonaldehyde

Crotonaldehyde[1]
Skeletal formula of crotonaldehyde
Ball-and-stick model of (Z)-crotonaldehyde
Names
IUPAC name
(2E)-but-2-enal
Other names
Crotonaldehyde
Crotonic aldehyde
β-Methacrolein
β-Methyl acrolein
2-butenal
Propylene aldehyde
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.021.846 Edit this at Wikidata
EC Number
  • 204-647-1
KEGG
RTECS number
  • GP9499000
UNII
UN number 1143
  • InChI=1S/C4H6O/c1-2-3-4-5/h2-4H,1H3/b3-2+ checkY
    Key: MLUCVPSAIODCQM-NSCUHMNNSA-N checkY
  • InChI=1/C4H6O/c1-2-3-4-5/h2-4H,1H3/b3-2+
    Key: MLUCVPSAIODCQM-NSCUHMNNBQ
  • O=C/C=C/C
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]
1.4362
Hazards
GHS labelling:
GHS02: FlammableGHS05: CorrosiveGHS06: ToxicGHS07: Exclamation markGHS08: Health hazardGHS09: Environmental hazard
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)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 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. gasolineInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazards (white): no code
4
3
2
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):
600 ppm (rat, 30 min)
1375 ppm (rat, 30 min)
519 ppm (mouse, 2 hr)
1500 ppm (rat, 30 min)[3]
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

cis-3-hexenal
(E,E)-2,4-Decadienal

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

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]

Uses

Crotonylidene diurea is a specialty fertilizer.[7]

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.[8] 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

  1. ^ Merck Index, 11th Edition, 2599
  2. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0157". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ a b "Crotonaldehyde". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ a b c 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.
  5. ^ 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.
  6. ^ Coburn, E. R. (1947). "3-Penten-2-ol". Org. Synth. 27: 65. doi:10.15227/orgsyn.027.0065.
  7. ^ 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.
  8. ^ 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.