Potassium Carbonate → 6-Chloropyridine-2,3-diamine

Temperature

60 °C

To a mixture of ethyl acetate (450 mL) and tert-butanol (50 mL), 6-chloro-3-nitropyridin-2-amine (CAS 27048-04-0) (15 g, 86.42 mmol), stannous chloride dehydrate (CAS 10025-69-1) (97.5 g, 432.1 mmol) were added. The resulting mixture was stirred at 60° C. for 1 hour. Sodiumborohydride (1.63 g, 43.21 mmol) was added and the mixture was stirred further at 60° C. for another 3 h. The mixture was cooled and stripped from the EtOAc on the rotavapor. The resulting residue was diluted with water (350 mL) and neutralized to pH=9-10 by addition of an aqueous solution of potassium carbonate. The resulting mixture was extracted with EtOAc (3×250 mL), dried over Na2SO4 and evaporated. The residue was stirred for 72 hours in a mixture of EtOAc/heptane 1/1. The precipitate was filtered and dried in vacuum for 2 hours. The intermediate 1-1 was collected as a greenish powder (9.32 g, 75%). m/z=144 (M+H)+.

1. additionwere added
2. stirringthe mixture was stirred further at 60° C. for another 3 h
3. temperatureThe mixture was cooled
4. extractionThe resulting mixture was extracted with EtOAc (3×250 mL)
5. dry with materialdried over Na2SO4
6. customevaporated
7. stirringThe residue was stirred for 72 hours in a mixture of EtOAc/heptane 1/1
8. filtrationThe precipitate was filtered
9. customdried in vacuum for 2 hours
10. customThe intermediate 1-1 was collected as a greenish powder (9.32 g, 75%)

ORD record

ord-41156a74ad014f4bb53b808c21c5860b

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08927720B2