4-Fluorophenol → 6-Fluoro-2-methyl-4-chromanone
Reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([OH:8])=[CH:4][CH:3]=1.[C:9](O)(=[O:13])/[CH:10]=[CH:11]/[CH3:12].[OH-].[Na+]>>[F:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:8][CH:11]([CH3:12])[CH2:10][C:9]2=[O:13]Participants
4
Conditions
- Temperature
- 120 °C
Procedure
11.2 G (0.1 mol) of para-fluorophenol and 17.2 g (0.2 mol) of crotonic acid were dissolved in 100 ml of polyphosphoric acid, and the solution was reacted with vigorously stirring at 120° C. for 8 hours. After cooling, the reaction solution was poured into 450 ml of iced 2N-sodium hydroxide solution, and the mixture was extracted with 500 ml of chloroform. The chloroform layer was washed with 2N-sodium hydroxide solution and with water, followed by drying over magnesium sulfate. The solvent was distilled off, and the residue was recrystallized from n-hexane in the amount of about ten times. There were thus obtained 5.8 g (yield : 32%) of the subject material, 6-fluoro-2-methyl-4- chromanone.
Workup
- customthe solution was reacted
- temperatureAfter cooling
- extractionthe mixture was extracted with 500 ml of chloroform
- washThe chloroform layer was washed with 2N-sodium hydroxide solution and with water
- dry with materialby drying over magnesium sulfate
- distillationThe solvent was distilled off
- customthe residue was recrystallized from n-hexane in the amount of about ten times
Sources & evidence
- ORD record
- ord-65487d07f7f24ca59ba0760bf2d3df6d
- Source dataset
- uspto-grants-1988_10
- Patent number
- US04780472
Reaction notes
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