Isobutyronitrile → 3,3'-Bis(2-methyl-2-cyanopropyl)biphenyl

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Reaction Steps

In a 500-ml flask, equipped with a magnetic stirrer, a reflux condenser capped with a nitrogen bubbler, a dropping funnel and a syringe adapter, was put 150 ml of anhydrous THF and 7.0 ml (5.05 g, 0.050M) of diisopropylamine (via syringe). The flask was cooled in a dry ice bath, and with stirring, 23.1 ml of 2.17 molar (0.050M) n-butyllithium in hexane was added via syringe. The mixture was stirred for 55 minutes, and then a solution of 3.42 g (0.049M) of freshly distilled isobutyronitrile in 10 ml of anhydrous THF was added dropwise in 7 minutes. After an additional 20 minutes of stirring, a solution of 8.50 g (0.0250M) of 3,3'-bis(bromomethyl)biphenyl in 75 ml of anhydrous THF was added during 38 minutes. The mixture was allowed to warm to room temperature as it stirred overnight. During the addition, the mixture developed an intense blue color. This color was still apparent on the day after the mixture had warmed to room temperature, but after two additional days of stirring at room temperature, the mixture was light brown and clear. The solvent was removed on the water pump and the resulting residue was dissolved in 200 ml of chloroform. Washing of this solution three times with 100 ml of water (with HCl acidification during the first washing), drying the solution over anhydrous magnesium sulfate, removal of the solvent on the water pump, and drying the resulting residue in vacuo, gave 7.50 g (95%) of crude 3,3'-bis(2-methyl-2-cyanopropyl)biphenyl melting at 96° to 103°. Dissolving this material in hot cyclohexane, refluxing the resulting solution with Darco, filtering through Celite, evaporating the filtrate to 125 ml, and cooling it at 8° to 10°, gave 5.36 g of the product as colorless prisms melting at 106.5° to 108.5°.

Provenance & Evidence