Pyridine → 4-chloro-N-(5-chloropyridin-2-yl)-2-nitrobenzamide

To a stirring suspension of 2-nitro-4-chlorobenzoic acid (20 g, 99 mmol) in dichloromethane (500 mL) was added a few drops of DMF, followed by oxalyl chloride (15.1 g, 119 mmol). After 1 h, the solvent was removed in vacuo and the residue was dissolved in dichloromethane (500 mL). To this stirring solution was added pyridine (24 mL, 297 mmol) followed by 2-amino-5-chloropyridine (12.7 g, 99 mmol). After stirring overnight, the solvents were removed in vacuo and the residue was stirred vigorously with ethyl acetate and water for several hours. The mixture was filtered to give a white solid, which was washed with ethyl acetate and dried in vacuo to give 23 g (74%) of the title compound. The combined ethyl acetate washings and extract were then washed twice with 1 M citric acid, once with brine, twice with saturated aq sodium bicarbonate, and again with brine. The organic phase was then dried with MgSO4, filtered and concentrated in vacuo. The solid was suspended in diethyl ether, sonicated and filtered to give a second crop of the title compound as a white solid (5.79 g, 19%).

1. customthe solvent was removed in vacuo
2. dissolutionthe residue was dissolved in dichloromethane (500 mL)
3. customthe solvents were removed in vacuo
4. stirringthe residue was stirred vigorously with ethyl acetate and water for several hours
5. filtrationThe mixture was filtered
6. customto give a white solid, which
7. washwas washed with ethyl acetate
8. customdried in vacuo

ORD record

ord-30f7bf1acb894d45adf7f91c0e0b1e69

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07700628B2