Benzylideneacetone

Benzylideneacetone

Names
IUPAC name (E)-4-Phenylbut-3-ène-2-one
Other names Benzalacetone Benzylideneacetone Methyl styryl ketone Benzylidene acetone
Identifiers
CAS Number	122-57-6 Y 1896-62-4 (trans) Y
ChEBI	CHEBI:217301 Y
ChEMBL	ChEMBL73639 Y
ChemSpider	21106584 Y
Jmol interactive 3D	Image
RTECS number	EN0330000
InChI InChI=1S/C10H10O/c1-9(11)7-8-10-5-3-2-4-6-10/h2-8H,1H3/b8-7+ Y Key: BWHOZHOGCMHOBV-BQYQJAHWSA-N Y InChI=1/C10H10O/c1-9(11)7-8-10-5-3-2-4-6-10/h2-8H,1H3/b8-7+ Key: BWHOZHOGCMHOBV-BQYQJAHWBQ
SMILES CC(=O)/C=C/c1ccccc1
Properties
Chemical formula	C10H10O
Molar mass	146.19 g/mol
Appearance	pale yellow solid
Density	1.008 g/cm3
Melting point	39 to 42 °C (102 to 108 °F; 312 to 315 K)
Boiling point	260 to 262 °C (500 to 504 °F; 533 to 535 K)
Solubility in water	1.3 g/L
Solubility in other solvents	nonpolar solvents
Hazards
Main hazards	irritant
R-phrases	36/37/38-43
S-phrases	22-26-36/37
Flash point	116 °C (241 °F; 389 K)
Related compounds
Related compounds	Dibenzylideneacetone cinnamaldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Benzylideneacetone is the organic compound described by the formula C₆H₅CH=CHC(O)CH₃. Although both cis- and trans-isomers are possible for the α,β-unsaturated ketone, only the trans isomer is observed. Its original preparation demonstrated the scope of condensation reactions to construct new, complex organic compounds.^[1]

Preparation

Benzylideneacetone can be efficiently prepared by the NaOH-induced condensation of the readily available reagents acetone and benzaldehyde:^[2]

CH₃C(O)CH₃ + C₆H₅CHO → C₆H₅CH=CHC(O)CH₃ + H₂O

Reactions

As with most methyl ketones, benzylidineacetone is moderately acidic at the alpha position, and it can be readily deprotonated to form the corresponding enolate^[3]

The compound undergoes the reactions expected for its collection of functional groups: e.g., the double bond adds bromine, the heterodiene adds electron-rich alkenes in Diels-Alder reactions to give dihydropyrans, the methyl group undergoes further condensation with benzaldehyde to give dibenzylideneacetone, and the carbonyl forms hydrazones. It reacts with Fe₂(CO)₉ to give (benzylideneacetone)Fe(CO)₃, a reagent for transferring the Fe(CO)₃ unit to other organic substrates.^[4]

References