6-fluoro-4-oxo-4H-chromene-2-carboxylic acid → 6-Fluoro-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

HRID 1265172Notes

Reaction equation

HRID 1265172 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([C:11]([OH:13])=[O:12])=[CH:8][C:7](=O)[C:6]=2[CH:15]=1.[H][H]>[Pd].C(O)(=O)C>[F:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]([C:11]([OH:13])=[O:12])[CH2:8][CH2:7][C:6]=2[CH:15]=1

Participants

5

Reactant 2

HCID 40960466-fluoro-4-oxo-4H-chromene-2-carboxylic acidHCID 178418361HCID 178418361, compound

Product 1

HCID 153828436-Fluoro-3,4-dihydro-2H-1-benzopyran-2-carboxylic acidYield 83%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolvent

Procedure

A mixture of 63.4 parts of 6-fluoro-4-oxo-4H-1-benzopyran-2-carboxylic acid and 400 parts of acetic acid was hydrogenated at normal pressure and at room temperature with 3 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was stirred in petroleumether. The product was filtered off and dried in vacuo at 70° C., yielding 49 parts (83%) of 6-fluoro-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid (int. 1).

Workup

  1. filtrationthe catalyst was filtered off
  2. customthe filtrate was evaporated
  3. filtrationThe product was filtered off
  4. customdried in vacuo at 70° C.

Sources & evidence

ORD record
ord-ad9707ec2bf94e2b801764bc2cc1c110
Source dataset
uspto-grants-2003_04
Patent number
US06545040B1

Reaction notes

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