Crotonaldehyde

Crotonaldehyde
Names
	IUPAC name (2E)-but-2-enal
	Other names Crotonaldehyde; Crotonic aldehyde; β-Methacrolein; β-Methyl acrolein; 2-butenal; Propylene aldehyde
Identifiers
CAS Number	4170-30-3 (E/Z) ; 123-73-9 (E) ; 15798-64-8 (Z) ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:41607 ;
ChEMBL	ChEMBL1086445 ;
ChemSpider	394562 ;
DrugBank	DB04381 ;
ECHA InfoCard	100.021.846
EC Number	204-647-1;
IUPHAR/BPS	6288;
KEGG	C19377 ;
PubChem CID	447466;
RTECS number	GP9499000;
UNII	9G72074TUW (E/Z) ; 6PUW625907 (E) ; RB9WCA91QT (Z) ;
UN number	1143
CompTox Dashboard (EPA)	DTXSID8024864 ;
	InChI InChI=1S/C4H6O/c1-2-3-4-5/h2-4H,1H3/b3-2+ Key: MLUCVPSAIODCQM-NSCUHMNNSA-N ; InChI=1/C4H6O/c1-2-3-4-5/h2-4H,1H3/b3-2+ Key: MLUCVPSAIODCQM-NSCUHMNNBQ;
	SMILES O=C/C=C/C;
Properties ((E) isomer)
Chemical formula	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)
Solubility in water	18% (20 °C)
Solubility	very soluble in ethanol, ethyl ether, acetone ; soluble in chloroform ; miscible in benzene
Vapor pressure	19 mmHg (20 °C)
Refractive index (nD)	1.4362
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H301, H310, H311, H315, H318, H330, H335, H341, H373, H400
Precautionary statements	P201, P202, P210, P233, P240, P241, P242, P243, P260, 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, P330, P332+P313, P361, P362, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501 Preview warning: Omit Rules: keep P320, omit P322 Preview warning: Omit Rules: keep P260, omit P261
NFPA 704 (fire diamond)	4 3 2
Flash point	13 °C (55 °F; 286 K)
Autoignition; temperature	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)
LCLo (lowest published)	400 ppm (rat, 1 hr)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 2 ppm (6 mg/m3)
REL (Recommended)	TWA 2 ppm (6 mg/m3)
IDLH (Immediate danger)	50 ppm
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). verify (what is ?) Infobox references

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. 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.