Methane → 7-Fluoro-4-hydroxy-2H-1-benzopyran-2-one

HRID 259674Notes

Reaction equation

HRID 259674 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([OH:8])[CH:5]=[CH:6][CH:7]=1.[C:9](O)(=[O:14])[CH2:10][C:11](O)=[O:12].P(Cl)(Cl)(Cl)=O.C>C(=O)([O-])O.[Na+].[Cl-].[Zn+2].[Cl-]>[F:1][C:2]1[CH:3]=[C:4]2[C:5]([C:9]([OH:14])=[CH:10][C:11](=[O:12])[O:8]2)=[CH:6][CH:7]=1

Participants

7

Reactant 4

HCID 297MethaneHCID 867Malonic AcidHCID 97433-FluorophenolHCID 24813Phosphorus oxychloride

Product 1

HCID 546945707-Fluoro-4-hydroxy-2H-1-benzopyran-2-one

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 516892Sodium BicarbonateSolvent

Conditions

Temperature
65 °C

Procedure

A mixture of 3-fluorophenol (31.5 g, 0.281 mol), malonic acid (29.24 g, 0.281 g) and zinc chloride (100.0 g, 0.734 mol) in phosphorus oxychloride (70 mL, 0.751 mol) is heated at 65° C. overnight and poured into an ice/water mixture. The resultant aqueous mixture is filtered to obtain a pale green solid. A mixture of the solid in 10% sodium hydrogen carbonate solution is stirred at room temperature for 2 hours, decolorized with charcoal and filtered through diatomaceous earth. The filtrate is acidified with concentrated hydrochloric acid and the resultant precipitate is collected and dried to give the title product as a brown solid, mp 229°-230° C.

Workup

  1. filtrationThe resultant aqueous mixture is filtered
  2. customto obtain a pale green solid
  3. filtrationfiltered through diatomaceous earth
  4. customthe resultant precipitate is collected
  5. customdried

Sources & evidence

ORD record
ord-945915dc136b456b964b39cc2c238c2b
Source dataset
uspto-grants-1996_06
Patent number
US05523278

Reaction notes

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