Ammonia → 2-Chloro-4,5-difluorobenzamide

To a solution (20 mL) of 2-chloro-4,5-difluorobenzoic acid (1.0 g) in N,N-dimethylformamide were added N-[3-(dimethylamino)propyl]-N′-ethylcarbodiimide hydrochloride (1.15 g) and N-hydroxysuccinimide (717 mg) under ice-cooling, and the mixture was stirred at room temperature for 1 hr. To the reaction mixture was added 28% aqueous ammonia solution (2 mL) under ice-cooling, and the mixture was stirred at room temperature for 30 min. Water was added to the mixture and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give 2-chloro-4,5-difluorobenzamide as a colorless solid (yield: 760 mg, yield: 76%). To a solution (5 mL) of 2-chloro-4,5-difluorobenzamide (300 mg) in N,N-dimethylformamide was added pyridine (0.253 mL), and oxalyl chloride (0.20 mL) was added dropwise thereto under ice-cooling. The reaction mixture was stirred at room temperature for 30 min, water was added to the mixture and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the title compound as a colorless solid (yield: 250 mg).

1. temperaturecooling
2. temperaturecooling
3. stirringthe mixture was stirred at room temperature for 30 min
4. extractionthe mixture was extracted with ethyl acetate
5. washThe extract was washed with saturated brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated under reduced pressure

ORD record

ord-987ca2ff4117486c95551e0848668aed

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08592452B2