1-Chloro-2,5-difluoro-4-nitrobenzene → 4-Chloro-2,5-difluoroaniline

1-Chloro-2,5-difluoro-4-nitrobenzene (XXXVIII) (17.5 g) was dissolved in acetic acid (150 ml) in a 1L 3-neck round bottom flask equipped with cooling condenser. To it iron powder (35.0 g) was added slowly while the solution was stirred by an overhead stirrer. The reaction was exothermic which occurred in less than 30 min and generated much heat that was absorbed by a cooling bath. After that, ethyl acetate (300 ml) was added and the mixture filtered. The solution was washed with water and dried over sodium sulfate. The product was purified by column chromatography (silica gel, hexane:ethyl acetate, 4:1) (14.3 g). 1H NMR (CDCl3, 300 MHz) 3.89 (2H, br), 6.56 (1H, m), 7.02 (1H, m) ppm.

1. customequipped
2. temperaturewith cooling condenser
3. waitoccurred in less than 30 min
4. temperaturegenerated much heat that
5. customwas absorbed by a cooling bath
6. additionAfter that, ethyl acetate (300 ml) was added
7. filtrationthe mixture filtered
8. washThe solution was washed with water
9. dry with materialdried over sodium sulfate
10. customThe product was purified by column chromatography (silica gel, hexane:ethyl acetate, 4:1) (14.3 g)

ORD-Eintrag

ord-ffde72d7c4134982802baf66738c6ff4

Quelldatensatz

uspto-grants-2002_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06355799B1