反应详情

To an ice-cold solution of 4-amino-2,5-difluorobenzonitrile (1.0 g) in anhydrous tetrahydrofuran (50 ml) was slowly added n-butyl lithium (2.6 ml) through an injector with stirring, followed by stirring 30 minutes. To the mixture was slowly added methanesulfonyl chloride (550 μl), followed by stirring at room temperature for 24 hours. After confirming the completion of the reaction using TLC, the resulting mixture was concentrated under reduced pressure, diluted with 1 N aqueous hydrochloric acid (100 ml), extracted with dichloromethane (50 ml×3). The combined organic layer was dried over magnesium sulfate, filtered, and then concentrated under reduced pressure. The obtained residue was purified by column-chromatography (ethyl acetate/hexane 2/3) to yield 2,5-difluoro-4-cyano-1-methanesulfonylaminobenzene (1.2 g, 79.6%).

1. stirringby stirring 30 minutes
2. stirringby stirring at room temperature for 24 hours
3. concentrationthe resulting mixture was concentrated under reduced pressure
4. additiondiluted with 1 N aqueous hydrochloric acid (100 ml)
5. extractionextracted with dichloromethane (50 ml×3)
6. dry with materialThe combined organic layer was dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe obtained residue was purified by column-chromatography (ethyl acetate/hexane 2/3)