Iodine → 3,3'-Difluoro-4,4'-dihydroxybiphenyl
Reaction equation
[Mg].Br[C:3]1[CH:8]=[CH:7][C:6]([O:9]C)=[C:5]([F:11])[CH:4]=1.[F:12][C:13]1[CH:14]=[C:15]([Mg]Br)[CH:16]=[CH:17][C:18]=1[O:19]C.II>O1CCCC1.[Pd](Cl)Cl>[F:11][C:5]1[CH:4]=[C:3]([C:15]2[CH:16]=[CH:17][C:18]([OH:19])=[C:13]([F:12])[CH:14]=2)[CH:8]=[CH:7][C:6]=1[OH:9]Participants
Procedure
Flaky metallic magnesium (2.43 g) was added to 50 ml of dry tetrahydrofuran, and while the mixture was heated, a solution of 20.5 g of 4-bromo-2-fluoroanisole in 100 ml of dry tetrahydrofuran was added dropwise little by little in a stream of nitrogen to prepare a tetrahydrofuran solution of 3-fluoro-4-methoxy-phenyl magnesium bromide. Then, 18.0 g of 4-bromo-2-fluoroanisole was added to 100 ml of dry tetrahydrofuran containing 0.05 g of iodine and 0.1 g of palladium chloride. The mixture was maintained at 40° to 50° C. in a stream of nitrogen, and the above-prepared tetrahydrofuran solution of 3-fluoro-4-methoxyphenyl magnesium bromide was added dropwise gradually. The addition was completely in about 1 hour, and thereafter, the mixture was reacted for 5 hours at the refluxing temperature of tetrahydrofuran. After the reaction, the reaction mixture was after-treated in a customary manner to give 38.2 g of a crude product. The desired product was isolated from the crude product by silica gel column chromatography using ethyl acetate/hexane as an eluent. Thus, 15.0 g of 3,3'-difluoro-4,4'-dimethoxybiphenyl was obtained.
Workup
- temperaturewhile the mixture was heated
- temperatureThe mixture was maintained at 40° to 50° C. in a stream of nitrogen
- additionThe addition
- customAfter the reaction
- additionthe reaction mixture was after-treated in a customary manner
- customto give 38.2 g of a crude product
Sources & evidence
- ORD record
- ord-58124f1e5f184e0584e4dfbb903888a6
- Source dataset
- uspto-grants-1990_03
- Patent number
- US04911862
Reaction notes
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