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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence