Isobutylamine → 2-Chloro-N-(2-methylpropyl)-6-methyl-3-nitropyridin-4-amine

Under a nitrogen atmosphere, a solution of 2,4-dichloro-6-methyl-3-nitropyridine (125 g, 0.604 mol) in anhydrous N,N-dimethylformamide (625 mL) was cooled to 0° C. Triethylamine (84.2 mL, 0.604 mol) was added. 2-Methylpropylamine (66 mL, 0.664 mol) was added dropwise to the resulting solution over a period of one hour; the reaction reached a temperature of 17° C. and became yellow. The reaction was allowed to warm to room temperature and stir overnight. The reaction mixture was filtered to remove salts, and then the N,N-dimethylformamide was removed under reduced pressure. The crude product was dissolved in ethyl acetate (750 mL), and the solution was washed with water (3×1 L), dried over magnesium sulfate, and then concentrated under reduced pressure. Hexane (300 mL) was added to the resulting yellow oil; the mixture was heated until the oil dissolved and then placed in a freezer. After ten minutes, the recrystallization mixture was seeded with crystals made in a previous run and then left undisturbed for four hours. The resulting precipitate was filtered, washed with cold hexane, and dried in a vacuum oven at room temperature to provide 98 g of 2-chloro-N-(2-methylpropyl)-6-methyl-3-nitropyridin-4-amine.

1. customa temperature of 17° C.
2. filtrationThe reaction mixture was filtered
3. customto remove salts
4. customthe N,N-dimethylformamide was removed under reduced pressure
5. dissolutionThe crude product was dissolved in ethyl acetate (750 mL)
6. washthe solution was washed with water (3×1 L)
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. additionHexane (300 mL) was added to the resulting yellow oil
10. temperaturethe mixture was heated until the oil
11. dissolutiondissolved
12. waitAfter ten minutes
13. waitleft undisturbed for four hours
14. filtrationThe resulting precipitate was filtered
15. washwashed with cold hexane
16. customdried in a vacuum oven at room temperature

ORD record

ord-51ad22c6f5484b828e18e18610e85e1c

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07038053B2