Dibenzoylmethane

Title: Dibenzoylmethane
CAS Registry Number: 120-46-7
CAS Name: 1,3-Diphenyl-1,3-propanedione
Additional Names: phenyl-a-hydroxystyryl ketone; w-benzoylacetophenone; phenyl phenacyl ketone; g-hydroxychalkone
Molecular Formula: C15H12O2
Molecular Weight: 224.25
Percent Composition: C 80.34%, H 5.39%, O 14.27%
Line Formula: C6H5COCH2COC6H5
Literature References: Prepd by the action of sodium methylate on benzylideneacetophenone dibromide: Allen et al., Org. Synth. coll. vol. I (2nd ed., 1941) p 205.
Properties: Orthorhombic plates, tablets from petr ether, mp 80°. bp18 219-221°. 100 parts alc dissolve 4.43 parts at 19°. Sol in ether, chloroform, aq NaOH. Equilibrium mixtures in methanol, alcohol, and glacial acetic acid contain 96-98% of the enol form.
Melting point: mp 80°
Boiling point: bp18 219-221°
Derivative Type: Monoxime
Molecular Formula: C15H13NO2
Molecular Weight: 239.27
Percent Composition: C 75.30%, H 5.48%, N 5.85%, O 13.37%
Properties: Prepd by adding 4 mols hydroxylamine to 1 mol dibenzoylmethane in alcohol. Prisms from ether, mp 165°. Sparingly sol in cold alcohol.
Melting point: mp 165°
Dibenzyl Chlorophosphonate Dibenzyl Disulfide Dibenzyl Phosphite Dibenzylamine Diborane(6)

Dibenzoylmethane
Dibenzoylmethane.svg
Identifiers
CAS number 120-46-7 YesY
PubChem 8433
ChemSpider 8126 N
Jmol-3D images Image 1
Properties
Molecular formula C15H12O2
Molar mass 224.25 g/mol
Melting point 77−78 °C [1]
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

1,3-diphenylpropane-1,3-dione (dibenzoylmethane, DBM) is an aromatic 1,3-diketone, acetylacetone (acac) derivative, where both methyl groups have been substituted by phenyl groups. It is white solid melting 77−78 °C. Similarly to acac, DBM exist as two tautomeric forms, however keto-enol equilibrium of DBM is strongly shifted to the enol form. It is result of formation of intra-molecular hydrogen bond, which is conjugated with phenyl rings.[1] The resonance-assisted hydrogen bond is responsible for high photostability of such compounds, and therefore, some derivates of DBM (e.g. Avobenzone) have found application as sunscreens.