Diphenylacetonitrile

UsesMathadone (M225865) impurity. Used in synthesis of methadone, antispasmodics and other pharmaceuticals.Diphenylacetonitrile is used to synthesize isocyanate, which is further prepared into UV paint, PU paint, transparent elastomer and adhesive, etc. In addition, it is also used in polyamide and epoxy resin industries.

General DescriptionDiphenylacetonitrile can be prepared in good yield by the dehydration of the amide of diphenyl acetic acid with phosphorous oxychloride.

PreparationDiphenylacetonitrile can be prepared in good yield by the dehydration of the amide of diphenyl acetic acid with phosphorous oxychloride. Diphenylacetonitrile undergoes anhydrous condensation with ethyl-4-bromo-butyrate. This is followed by its hydrolysis in alkaline medium that is used in the quantitative determination of 3-cyano-3,3-diphenylpropionic acid.

PreparationIn a 100 mL, nitrogen-flushed pear flask was added indium(III) bromide (2.0 mmol, 10 mol %) in CH2Cl2 (40 mL) to give a white suspension. To this at room temperature was added trimethylsilyl cyanide (40 mmol, 2.0 equiv.), followed by dropwise addition of alcohol (20 mmol, 1.0 equiv.) to give a moderate exothermic reaction. The mixture slowly turned clear, and TLC showed mostly the desire product. Saturated NaHCO3 was added and the mixture was concentrated in vacuo to remove the volatiles. The residue was partitioned between saturated NaHCO3 and ethyl acetate, and the aqueous layer was extracted one more time with ethyl acetate. Combined organic layers were dried over MgSO4, filtered and concentrated. The crude product was purified by flash column chromatography on silica gel (5% ethyl acetate/hexanes) to give the desired Diphenylacetonitrile.