Dimethylformamide → 2-(5-Fluoro-2-nitroanilino)benzo[b]thiophene-3-carbonitrile

Temperature

55 °C

To a solution of 2-aminobenzo[b]thiophene-3-carbonitrile (116 g), dimethylformamide (370 ml) and 2,4-difluoronitrobenzene (73 ml) was added pulverized potassium carbonate (276 g), and the mixture was stirred at 55° C. for 5.5 hours. The reaction mixture was stirred under ice-cooling for 30 minutes and water (1.9 L) was added. The mixture was further stirred for 30 minutes. The precipitated crystals were filtered by suction and washed with water (1.9 L) and dried in a drying box overnight to give crude crystals (198 g). The obtained crude crystals were suspended in ethyl acetate (700 ml) and the mixture was stirred under reflux with heating while removing water for 2 hours. The reaction mixture was cooled and stirred at 20° C. for 1 hour. The precipitated crystals were filtered by suction, washed with ethyl acetate (150 ml) and dried to give 2-(5-fluoro-2-nitroanilino)benzo[b]thiophene-3-carbonitrile (123 g) as red crystalline powder.

1. stirringThe reaction mixture was stirred under ice-
2. temperaturecooling for 30 minutes
3. stirringThe mixture was further stirred for 30 minutes
4. filtrationThe precipitated crystals were filtered by suction
5. washwashed with water (1.9 L)
6. customdried in a drying box overnight
7. customto give crude crystals (198 g)
8. customThe obtained crude crystals
9. stirringthe mixture was stirred
10. temperatureunder reflux
11. temperaturewith heating
12. customwhile removing water for 2 hours
13. temperatureThe reaction mixture was cooled
14. stirringstirred at 20° C. for 1 hour
15. filtrationThe precipitated crystals were filtered by suction
16. washwashed with ethyl acetate (150 ml)
17. customdried

ORD record

ord-45621fd7469543819eaa9f7da9f61223

Source dataset

uspto-grants-2001_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06271225B1