Ammonia → 2-Amino-7-nitroacridin-9(10H)-one

See Korolev et al., 1976. Polyphosphoric acid was freshly prepared by slowly adding, with stirring, 85% orthophosphoric acid (360 mL) to phosphorus pentoxide (600 g). The mixture was then heated on a steam bath with stirring until a clear viscous liquid was obtained. 2-(-4-amino-phenylamino)-5-nitrobenzoic acid 10 (107.76 g, 0.394 mol) was added with stirring over the course of 5 min. Heating on the steam bath was continued for 6 hr, the mixture being stirred occasionally. Whilst still hot, the mixture was poured into 4 L of ice-water, stirred for 30 min, and allowed to stand overnight. The mixture was adjusted to pH 8.0 by the addition of 0.88 s.g. aqueous ammonia, chilled for 2 hr, and the crude product collected on a glass sinter. It was washed with dilute ammonia (1% 0.88 s.g. aqueous ammonia in water, 250 mL) followed by water (3×250 mL), ice-cold ethanol (2×250 mL), dry ether (2×250 mL) and finally hexane (250 mL). The product, 11, was dried over P2O5 under vacuum to yield a red-brown solid (97.04 g, 96%).

1. additionby slowly adding
2. temperatureThe mixture was then heated on a steam bath
3. stirringwith stirring until a clear viscous liquid
4. customwas obtained
5. stirringwith stirring over the course of 5 min
6. temperatureHeating on the steam bath
7. stirringthe mixture being stirred occasionally
8. stirringstirred for 30 min
9. waitto stand overnight
10. additionThe mixture was adjusted to pH 8.0 by the addition of 0.88 s
11. customthe crude product collected on a glass sinter
12. washIt was washed with dilute ammonia (1% 0.88 s.g. aqueous ammonia in water, 250 mL)
13. dry with materialThe product, 11, was dried over P2O5 under vacuum

ORD record

ord-ed36185beb5244a0849b932c86d28fc3

Source dataset

uspto-grants-2007_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07160896B2