31643-49-9

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4-Nitrophthalonitrile is a useful chemical in organic synthesis. Dyes and metabolites.

Synthesis of 4-Nitrophthalonitrile: SOCl2 (83.5 mL. 1.144 mol) was added dropwise under nitrogen purge to dry DMF (200 mL) which had been cooled to 0-5 °C. The solution was allowed to stir for 15 min at 0-5 °C. The 4-nitrophthalamide (60.1 g, 0.286 mol) was then added and the solution was allowed to slowly warm to room temperature and react for 18 h under nitrogen purge. The solution was then slowly added to ice water to crystallize and precipitate the product. The 4-nitrophthalonitrile was collected using vacuum filtration, washed with ice cold water, and allowed to air dry overnight; yield: 45.2 g (92%); m.p.: 141 °C (det. by DSC)
1 H NMR((CD3)2SO): 8.41 (dd, 1H), 8.67 (dd, 1H), 9.03 (dd, 1H) FTIR: 3091 (m, aromatic C-H stretch), 2242 (d, CN stretch), 1534 (s, asymmetric N=O stretch), 1349 (s, symmetric N=O stretch), 853 (s, C-N stretch)

In a three necked flask, 70 mL of dry dimethylformamide (DMF) was cooled to 0 °C under a stream of nitrogen and 7.3 mL of thionyl chloride was added so that the internal temperature did not go beyond 5 °C. After addition, nitrogen flow was ceased and a calcium chloride tube was added to the top of flask. Meanwhile, the color of the medium was observed to be yellow. Then, 10 g (0.048 mol) of 4- nitrophthalamide was slowly added so that the internal temperature did not go beyond 5 °C. The mixture was stirred over ice bath for 1 hour. The mixture was stirred at room temperature for 2 hours and then poured over 500 g of ice-water. The precipitate was filtered and washed successively with water, 250 mL 5% sodium hydrogencarbonate solution, and water again and dried in a vacuum oven at 110-120 °C. Molecular formula: C8H3N3O2. Yield: 7.4 g (90%). Mp: 141 °C.