Triphenylphosphine → 4-(4-Chlorophenyl)benzonitrile

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Reaction Steps

4-chlorophenylmagnesium chloride (114 g, 18% solution in tetrahydrofuran) is added dropwise over seven hours to a refluxing solution of 4-bromobenzonitrile (20 g), palladium (II) chloride (0.78 g ) and triphenylphosphine (2.3 g) in tetrahydrofuran (100 ml). [HPLC: yield 75-79%]. After cooling to room temperature tetrahydrofuran is removed under vacuum. The residue is taken up in toluene/water (1:1) (200 ml) and filtered. The aqueous phase is separated off, and the solvent removed by distillation. The crude product is recrystallised from isopropanol/ethanol to give 4'-chlorobiphenyl-4-carbonitrile as a solid, m.pt. 128-130° C. 1H NMR (CDCl3): 2.41(s,3H), 7.46(d,2H), 7.53(d,2H), 7.65(d,2H), 7.74(d,2H).

Provenance & Evidence