Acrylic Acid → 7-fluoro-3,4-dihydro-2H-1-benzopyran-4-one

HRID 981789Notes

Reaction equation

HRID 981789 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([OH:8])[CH:5]=[CH:6][CH:7]=1.[C:9](O)(=[O:12])[CH:10]=[CH2:11].C1C2NC3C(=CC=CC=3)SC=2C=CC=1>>[F:1][C:2]1[CH:3]=[C:4]2[C:5]([C:9](=[O:12])[CH2:10][CH2:11][O:8]2)=[CH:6][CH:7]=1

Participants

4

Reactant 3

HCID 6581Acrylic AcidHCID 7108PhenothiazineHCID 97433-Fluorophenol

Product 1

HCID 146531327-fluoro-3,4-dihydro-2H-1-benzopyran-4-one

Conditions

Temperature
-78 °C

Procedure

Following the same procedure established in Example 1, the reactor was charged with meta-fluorophenol (28 grams), acrylic acid (27 grams), and phenothiazine (0.02 grams). The reactor was sealed, evacuated and cooled to -78° C. before the anhydrous hydrogen fluoride (125 grams) was added. The mixture was stirred and warmed to 40° C. for one hour then to 100° C. for 4.5 hours as the pressure was recorded at 140 psig. After venting the excess hydrogen fluoride the reactor was cooled to 5° C. and the mixture washed with D.I. water. Analysis by HPLC indicated no 4-Chromanones to be present. A mixture of by-products were seen.

Workup

  1. customThe reactor was sealed
  2. customevacuated
  3. additionwas added
  4. temperaturewarmed to 40° C. for one hour
  5. temperaturewas cooled to 5° C.
  6. washthe mixture washed with D.I
  7. additionA mixture of by-products

Sources & evidence

ORD record
ord-8dc47a71f81e42a79547212ce9f1e4b5
Source dataset
uspto-grants-1991_02
Patent number
US04992564

Reaction notes

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