Sulfuric Acid → 2-Ethylhexyl 4-amino-3,6-dichloropyridine-2-carboxylate

To a solution of 2-ethylhexanol (10 mL) and sulfuric acid (1 mL) was added 4-amino-3,6-dichloro-pyridine-2-carboxylic acid (0.0097 mol, 2.0 g). After heating the reaction to reflux overnight, the reaction mixture was cooled, poured into water (75 mL), and extracted with ethyl acetate (75 mL). The organic phase was washed with sodium bicarbonate (75 mL), dried (Na2SO4), and concentrated. The resulting solid was recrystallized out of dichloromethane and hexane and filtered to give 2-ethylhexyl 4-amino-3,6-dichloropyridine-2-carboxylate (0.0074 mol, 2.36 g) as a crystalline solid (mp 55° C.). 1H NMR (CDCl3): δ 0.9 (7 H, m), 1.3 (7 H, m), 1.7 (1 H, m), 4.3 (2 H, d), 5.1 (2 H, bs), 6.7 (1 H, s).

1. temperatureAfter heating
2. customthe reaction
3. temperatureto reflux overnight
4. temperaturethe reaction mixture was cooled
5. extractionextracted with ethyl acetate (75 mL)
6. washThe organic phase was washed with sodium bicarbonate (75 mL)
7. dry with materialdried (Na2SO4)
8. concentrationconcentrated
9. customThe resulting solid was recrystallized out of dichloromethane and hexane
10. filtrationfiltered

ORD record

ord-01f78302bb844d9c899e5af333717ca4

Source dataset

uspto-grants-2001_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06297197B1