4′-Amino-4,4″-dimethoxy-[1,1′:3′,1″-terphenyl]-5′-carbonitrile (226 mg, 0.68 mmol) was heated in ethanol (28 mL) to bring most of the material into solution. After cooling to room temperature, 17% aqueous HCl (4 mL) was added and the reaction was cooled in an ice bath. Sodium nitrite (76 mg, 1.09 mmol) was added and the orange-red solution was stirred for 15 min in the ice bath. Sodium azide (71 mg, 1.09 mmol) was then added. After 20 min, the reaction was partitioned between ethyl acetate and sufficient saturated aqueous sodium bicarbonate to neutralize the reaction. The organic phase was separated, washed with brine, and dried with sodium sulfate. Silica gel radial chromatograph using step gradient elution with hexane containing 5 to 20% ethyl acetate afforded 4′-azido-4,4″-dimethoxy-[1,1′:3′,1″-terphenyl]-5′-carbonitrile (108 mg, 44%) as a solid. 1H NMR (500, CDCl3) δ ppm 7.72 (1H, d, J=2.14 Hz), 7.62 (1H, d, J=2.14 Hz), 7.47 (2H, d, J=8.55 Hz), 7.39 (2H, d, J=8.55 Hz), 7.01 (2H, d, J=8.55 Hz), 6.97 (2H, d, J=8.85 Hz), 3.87 (3H, s), 3.84 (3H, s).
