Hydrochloric Acid → 1,2-Benzenedicarbonitrile, 4-nitro-

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Reaction Steps

4-nitrophthalamide (220 g; 1.05 moles) is suspended in pyridine (840 ml). Into this vigorously stirred suspension, phosphorus oxychloride (220 ml; 2.40 moles) is added at such a rate that the reaction maintains a temperature range of 65°-70° C during the 30-minute addition time. The same temperature is maintained an additional hour by external heating. The resulting mixture is neutralized with 12 N hydrochloric acid (150 ml). The purple solid is collected by filtration and dried. The residue is extracted with ethyl acetate (3 × 700 ml) and the purple extract is decolorized with activated charcoal, washed first with 0.4N sodium hydroxide saturated with sodium chloride (3 × 70 ml) and then with water (4 × 70 ml). Drying and evaporation of the extract leaves 91 g of II as pale yellow crystals; yield, 50%; mp 142-144°; lit. (7-mp 138°-139°; lit. (4) 142°.

Provenance & Evidence