反应详情

4-nitrophthalamide (220g; 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 0.4 N sodium hydroxide saturated with sodium chloride (3 × 70 ml) and then with water (4 × 70 ml). Drying and evaporation of the extract leaves 91g of II as pale yellow crystals; yield, 50%, mp 142°-144° C; lit. (7) mp 138°-139° C; lit. (4) 142° C.

1. customa temperature range of 65°-70° C
2. additionduring the 30 minute addition time
3. temperatureThe same temperature is maintained an additional hour by external heating
4. filtrationThe purple solid is collected by filtration
5. customdried
6. extractionThe residue is extracted with ethyl acetate (3 × 700 ml)
7. extractionthe purple extract
8. washwashed first with 0.4 N sodium hydroxide saturated with sodium chloride (3 × 70 ml)
9. customDrying
10. customevaporation of the extract