Pyridine → 5-Chloro-2-nitro-n-(2-pyridyl)benzamide

To a stirring solution of 5-chloro-2-nitrobenzoic acid (15 g, 74 mmol) in dichloromethane (300 mL) was added DMF (a few drops) followed by oxalyl chloride (11.3 g, 89 mmol). After stirring for 2 h, the solvent was removed in vacuo and the residue was redissolved in dichloromethane (300 mL). To this stirring solution was added pyridine (17.5 g, 222 mmol), followed by 2-aminopyridine (7 g, 74 mmol). After 24 h, the solvent was removed in vacuo and the residue was partitioned between ethyl acetate and water. The organic phase was separated and washed twice with 1 M citric acid, once with brine, twice with satd aq NaHCO3, and once with brine. The organic phase was then dried (MgSO4), filtered and concentrated in vacuo to a volume of about 25 mL, then diluted with diethyl ether, and sonicated. The resulting precipitate was filtered and dried in vacuo to give 8.63 g (42%) of an off-white solid.

1. customthe solvent was removed in vacuo
2. dissolutionthe residue was redissolved in dichloromethane (300 mL)
3. waitAfter 24 h
4. customthe solvent was removed in vacuo
5. customthe residue was partitioned between ethyl acetate and water
6. customThe organic phase was separated
7. washwashed twice with 1 M citric acid, once with brine, twice with satd aq NaHCO3
8. dry with materialThe organic phase was then dried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo to a volume of about 25 mL
11. additiondiluted with diethyl ether
12. customsonicated
13. filtrationThe resulting precipitate was filtered
14. customdried in vacuo

ORD record

ord-f7596e38ecfc49d88a9af00ccb68e8ae

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06605626B2