7-hydroxy-2-methyl-4H-chromen-4-one Property

Melting point:

254-255℃

Boiling point:

345.5±42.0 °C(Predicted)

Density 

1.319±0.06 g/cm3(Predicted)

storage temp. 

Inert atmosphere,Room Temperature

pka

7.07±0.40(Predicted)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

7-hydroxy-2-methyl-4H-chromen-4-one Chemical Properties,Usage,Production

Uses

7-Hydroxy-2-methyl-4H-chromen-4-one is used in the synthesis of 2,2-Dimethyl-2H-pyranoflavonol and pyranochromone derivatives.

Synthesis

Step(i): 7-Acetoxy-3-acetyl-2-methylchromone β-Resacetophenone (4.A.6) (10 g，0.066 mole) is heated with fusedsodium acetate (20 g) in acetic anhydride (30 ml) for 5 hr at 170-180°(oil bath) under anhydrous conditions. The reaction mixture is pouredover crushed ice, stirred well and left overnight.The separated product isfiltered and washed with water. It is crystallised from alcohol as light yellowneedles.Yield 10 g (58.5%).M.p.127° (lit. m.p.126-27°).
step (ii) : The above 7-acetoxy-3-acetyl-2-methylchromone (1 g,0.0038 mole) isrefluxed (2 hr) with aqueous sodium carbonate solution (10%,50 ml).Theclear solution is then acidified with hydrochloric acid (1:1).The separatedproduct is filtered and washed with water. It is crystallised from alcohol asthick prismatic crystals. Yield 0.5 g (73.5%).M.p. 249-50°.(lit. m.p.254-55°).