Sulfuric Acid → HCID 20253634, compound

To a mixture containing 16.7 g of 5-phenyl-1,6-naphthyridin-2(1H)-one and 250 ml of concentrated sulfuric acid was added portionwise 7.6 g of potassium nitrate with stirring, keeping the mixture in an ice bath. The addition was completed within 15 minutes and the temperature of the reaction mixture was kept below 10° C. during addition. The reaction mixture was then stirred in the ice bath for 40 minutes, allowed to warm up to room temperature and then stirred at room temperature for 5 and 1/2 hours. The reaction mixture was poured over ice and the resulting mixture was made basic using concentrated ammonium hydroxide solution. The mixture was made slightly acidic using glacial acetic acid and chilled. The separated solid was collected and dried. The solid was recrystallized from boiling dimethylformamide using decolorizing charcoal, the hot mixture filtered and the filtrate chilled. The separated solid was collected, washed with ethanol and dried in a vacuum oven at 90° C. to yield 12.2 g of 5-(3-nitrophenyl)-1,6-naphthyridin-2 (1H)-one, m.p. >300° C.

1. additionThe addition
2. additionthe temperature of the reaction mixture was kept below 10° C. during addition
3. stirringstirred at room temperature for 5 and 1/2 hours
4. additionThe reaction mixture was poured over ice
5. temperaturechilled
6. customThe separated solid was collected
7. customdried
8. customThe solid was recrystallized
9. filtrationthe hot mixture filtered
10. temperaturethe filtrate chilled
11. customThe separated solid was collected
12. washwashed with ethanol
13. customdried in a vacuum oven at 90° C.

ORD record

ord-a4df46e8dd9b4383967a4696c8c2d0eb

Source dataset

uspto-grants-1985_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04560691