Sulfuric Acid → 4'-Ethyl-2-fluoro-1,1'-biphenyl

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Reaction Steps

1-Ethynyl-4-(2-fluorophenyl)benzene, 22 g, was reduced in a Parr Instrument Company Series 3910 Low Pressure Shaker-type Apparatus, using 100 ml of benzene, 2 g of five percent palladium on charcoal, and 0.5 ml of concentrated sulfuric acid. Reduction was carried out at room temperature and at an initial hydrogen pressure of 50 psig. Within 15 minutes, the hydrogen pressure had dropped to 32 psig. Hydrogen pressure was increased to 52 psig and agitation continued for two hours, with no additional hydrogen pressure drop. The reaction mixture was filtered and the filtrate was neutralized with two percent aqueous sodium carbonate. The resulting mixture was washed with water. The benzene phase was separated, dried over anhydrous sodium sulfate, and filtered. The benzene was evaporated and the residue was vacuum distilled to give 17 g of 1-ethyl-4-(2-fluorophenyl)benzene, bp 99°-101°/0.3 mm. The following elemental analysis was obtained:

Provenance & Evidence